For me it’s a toss up between:
Sticking 2p pieces on packets of cigarettes which give the customer change from vending machines. A roll of tape, a pile of coins and a stack of packs of cigarettes. Aaaarrrgggg!
Pea sorting! Along a conveyor belt. You got bonuses for picking out rodents etc. One of the workers smuggled in a sheep’s head (?!) and attempted to claim per head on the maggots!
That would have to be shelving books at the library. Day in, day out, it was looking at the spine of the books, figuring out where to place it properly, and the next day, come in to find that the exact same book needs to be shelved again. I did it for about a year. It was like I was trapped in a never ending nightmare. shudders at the memory
I temped once for a drug company that had sent out about a million vials of a brand-new tester drug, for, well, testing. The tests results had come in and the vials were being recalled.
So day after day after day three of us little temps were put in the basement counting boxes and boxes of vials. Each box had sixteen vials. But we couldn’t do a visual inspection. We had to physically count each one, or the supervisor would yell at us.
Boxes and boxes and boxes…
I lasted one month. And then I quit. I was so pissed at the temp agency - let’s say them loud and clear - MANPOWER. They promised me an office job and this is what I got. I was pissed at them already for being called MANpower when they had more female employees in the office, and more female temps. But that was minor.
After that I went to Office Team, who treated me much better.
Right now I’m doing medical records filing for the vet hospital I work at for extra cash. I have to go to the records area in the hospital and pull out all the ones over 3 years old, take them to the “container” (un-cooled trailer in the sun) and file them there, while removing the ones over 15 years old (because otherwise the new ones won’t fit in the shelves) and take the really old ones to the basement for scanning. Did I mention that the “container” had a leak problem a few years back and has the entire middle section’s files coated in mold?
I’ve never had an entirely mundane job, but portions of some of them were awful. Filing of any kind is horrid. Switchboard is horrid.
Please hold.
Please hold.
Please hold.
Page.
Page.
Page.
Thank you. I can connect you now.
Thank you. I can connect you now.
Thank you. I can connect you now.
He is NOT a horse’s ass.
He is NOT a horse’s ass.
He is NOT a horse’s ass.
Spent one summer working at my state’s department of motor vehicles processing vehicle registrations.
So…every day, opening hundreds and hundreds of envelopes and sorting the checks, registration forms, and property tax receipts into pigeon holes. (If I had a nickel for every check with “forty” spelled “fourty” on it, I’d be rich.)
Then, if we got through the day’s registrations, we stuffed envelopes. That part was so mundane that I would bring a book in, prop it up in front of me, and read while I stuffed.
Filing into the card catalog at a university library.
Expanding, then contracting subject index for same library.
it was so boring that there were days I would look at “book” and say to myself “B O O K … is that a word ?”
Oh dear - even the description “shelving books” sounds drear!
Shrink-wrapping rolls of wallpaper.
I was only 15 at the time, but I only lasted two weeks at that job before I just didn’t bother coming back.
My work-study job at my university’s Treasurer’s office was booooooooring.
My job duties (in a nutshell):
File insurance forms in a filing cabinet that was way too small to hold all the insurance forms. If the files were packed any more densely, the cabinet would have become the center of a new black hole.
Run around campus delivering faxes that had come in over the past 24 hours. At the time, the university had only one fax machine. Anytime someone needed to fax something to a member of the faculty, it came to my machine. Then I had to run around campus hand-delivering faxes. Seemed to me to defeat the purpose.
Stuffing envelopes.
This wasn’t one of those do it at home jobs, it was at a warehouse. It was for Val-Pack, they mass mail bunches of coupons. It was tedious, and resulted in numerous paper cuts. Apparently they thought I was talented so they moved me up to the envelope opening machine. It would open up the envelopes so they were easier to stuff. At least that allowed me to move around more because we had to deliver our boxes of oprned envelopes to the various stuffing stations. The warehouse was located near a bayou and their were always hordes of mosquitos waiting for us. I swear I got sleeping sickness from one of those mosquitos. That was the most exciting thing about the job.
Filing invoice forms in a great big room full of folders containing nothing but more invoice forms. Eight hours a day, all by myself. The only time I ever saw anyone else was when they stopped by the inbox to fill it with more invoice forms and I happened to be standing nearby.
I was a temp and I was filling in for a woman who was on maternity leave. After 3 weeks and an assload of paper cuts, I asked for another assignment. I still can’t believe that was someone’s full-time job.
romansperson, perhaps you shouldn’t have been filling out the invoices with your ass. How did you do that anyway? 
Ouch! No wonder she asked for a transfer!
Verrry carefully …
I can tie knots in cherry stems with my tongue too 
I worked in the reference section of our university library. The work was pretty simple, do about 15 min of shelving, then sit there and study. I usually worked the late night shift (9-10 or so), so the library was pretty dead. I had access to my bosses computer, so if I didn’t have any studying to do after I was finished, I would chat with friends online, while getting paid… Similar to what I do now, I just get paid more. 
Easy, it was a trained donkey.
I once temped for an agency that sent me out to a little industrial park in the middle of nowhere. I had to sit at a table where they’d bring trays of cellphone shells and you’d have to put little drops of glue on the little Xs. 6 drops per shell. 25 shells per tray. For eight hours straight in a loud manufacturing setting.
When I left that day my brain was fried and my eyes wouldn’t focus correctly.
I didn’t go back.
I remember the ladies that worked there permanently giving me snide looks at the end of the day saying “It’s not as easy as it looks, eh?” and feeling sorry for them as their brains turned to mush doing that as a full-time job.
It took me two reads to get this. Very funny. No sarcasm, I mean it.
The most mundane job I ever had was working as a Lab Monkey at my university during the summer. I worked there for a year and during the Fall and Winter semesters it was mostly sitting in a lab watching people work and refilling printers every now and then, but that was mile-a-minute excitement compared to the summer.
During the summer I worked in the nice new Health Services building they had built down town where all of the nursing and medical classes were. In this building I would actually work out of an office separate from the labs and I was supposed to go through and the check the labs several times an hour. The thing was there were only 2 or 3 classes per week in the building during the summer so there were rarely any students using the labs before and after their classes (when most people did their work). On top of that the nice new building only had parking for faculty so if a student wanted to use the labs when they weren’t already there for class they either had to pay high hourly parking prices or park at the main down town campus (where there were several more computer labs), walk to the bus stop, wait 30-60min for a bus, and take a 10min bus ride to the building. I would go for entire eight hour shifts and see only one student in the building.
It gets better. Several days a week the labs would close as of 5pm (when they began to get the idea that people weren’t using them they decided that they could shut them down and save some power), on those days my shifts would still go until 10pm. That’s right, for 5 hours I would be lab-sitting labs that were shut off and locked in an empty building.
Essential I would sit in the office for 4-8 hour shifts and lurk on the SDMB (as this was before I actually joined). I would like to take this time to make a formal announcement of thanks to the good members of this message board for keeping me sane through that summer.