My death pool list, in the extremely unlikely event one of the 13 kicks off.
My cell phone number (I never use the damn thing)
A sticky with codes for a couple of IM smilies I like
My library card number, for placing holds at their website
My business card (after the third time I had to dig one out to give someone the fax number)
A stickie with the following:
Nothing.
I like my monitor clean, neat, unencumbered.
You’ll be astonished to learn that even at work, where I’ve got a flat-screen monitor I can’t bring myself to tape anything to – I have a tiny stuffed lizard perched on the top. 'Cause I can’t just leave it with, yanno, no imposition of my personality… 
I read the title as “What’s taped to your mother?” Twice.
To answer the actual question, nothing (I have a laptop; there isn’t any room to tape things). I do have three notepads next to me on my desk, though.
You should start a thread – it might be interesting… 
I don’t have anything taped to my monitor (it’s distracting!), but I do have a plush Dogbert sitting atop it.
I used to keep Post-its® with passwords on them, but now I keep all pws in a little address book. There nothing on the monitor but dust. Boy, I gotta clean this thing. I have a little cat who cleans the inside, but I have to do the outside myself.
At home, nothing.
At work, two post it notes that my younger daughter wrote for me years ago, telling me she loves me (I need those to remind me of this when she calls asking for something).
I have my monitor stacked on 3 reams of paper and that’s where stick my most important notes–the system password requirements and “If it doesn’t work, it’s probably the join!” Stupid database and reporting software…
A sticky with my FAFSA PIN on it, another with an Experian credit report # (long since expired, I think I’ll chuck that one, yoink) and another reminding me to grab my lunch out of the fridge and turn the crockpot on before I leave for work (also now useless).
Thor.
Not a thing, though that’s partly because it’s a laptop and there’s no room. I’ve been known to modify my wallpaper by typing reminders of major upcoming deadlines over it though. (Always in a separate file so I can revert after the deadline.)
I have one small blue post-it attached to the bottom left corner. On it, there is a six-digit number, followed by a 5-digit dollar amount.
I have no idea what it’s for. 
I have a little cartoon sticker of Curious George flying a kite at the bottom, a pretty butterfly sticker at the top, and twickster reminded me to put my tiny little plastic lizard back on the top. That’s about all I want on it. And I also read the title as “What’s taped to your mother?” Sheesh - we really are a weird bunch 'round here.
A shiny 4-leaf clover sticker.
A bit of masking tape with “CLOSE PROGRAMS AND LOG OFF” written on it, to remind my mother what to do when she’s done with the computer.
Sitting on top is a little stuffed lizard. He’s filled with sand, I think, and he’s fun to play with.
I have a little table on how to get special characters in the Leroy font in Microstation (a CAD program) and a sticky on how to print to the big plotter (requires a DOS command). And on top of the right monitor (I have a two monitor system), I’e got a little hand painted Mexican turtle with a bobble head.
Pretty dull…
Nothing taped to it, but my stapler sits right on top of it, along with a couple on index cards.
Hallmark’s stores are ‘Gold Crown’ stores, whatever that means. What it means as far as I’m concerned, is that on the rare occasion I find myself buying a Hallmark card actually in a Hallmark store, I get a cool sticker to seal the envelope with.
So the only thing on my monitor are these four little gold crown stickers to go with my royal username, see?
Why, yes, I’m aware of my dorkiness, of course. :o
At home, nothing.
At work, a list of everyone’s phone extensions, a couple of phone numbers that I never remember, plus a selection of Japanese phrases that only get used when taking phone messages.
There’s also a mini-Aibo keychain and a Cup Noodle alien perched on top.
Here at home - nada
At work? My 17-in flat screen looks like a demented daisy. Multi-color post-its, in some places 4 stickies deep. It’s a thing of desperate beauty and inspired architecture. Numbers for everything from the Mayor’s office to the Coast Guard, the State Epidemiologist to the FBI, and every single emergency management office on the coast. And quotes?
And yes every single one of those post-its are important!
At the moment, a single post-it note with scrawled phone numbers on it I should use and call soon if I don’t want my arse kicked (I’m too forgetful).
Sometimes, there are a line of those notes under the screen, acusing me silently …