rewindable DVDs. The clerk at Blockbuster is running out of reasons to be grumpy.
As Enigma42 pointed out, something like this does exist. The fretlight guitar. I haven’t tried it, but there are reviews on the website.
And don’t butts have built-in kazoos?
Oral-B’s Sesame Street package of kids’ toothpaste is appealingly fruit-punch flavored. Much better than that minty stuff.
Corr, who adores kids’ toothpaste
The problem is that they would be crunched into little pieces by the dumbfucks who drive Cadillac Super SUVs or the equivalent - the Cadillac SUVs are the most virulent strain, but the Eddie Bauer Special Editions are right up there.
I believe that all men have butt kazoos. 
Bwaaahhhhaaa, I had one an hour or two ago 
I’d like a donut making machine like the one at Krispy Kreme, scaled down into a practical kitchen appliance.
There’s this, but you have to build it yourself.
peristaltic bathtub drains. never clog.
Tobacco-leaf shaped marijuana
Chopsticks with thumb-actuated grappling prongs in the tip
I’d like someone to genetically engineer kudzu, crabgrass, or some other ‘pest’ plant to produce THC. I know they could do it, I’ve seen a tobacco plant that glowed because they grafted in a gene from a firefly.
The equivalent of 8 hours of sleep in a can.
I will someday make that, and I will be rich. Awakeness is really just regulated by chemical output in the brain. I’m sure we have the technology to “prescribe” awakeness in doses and blend it into a refreshing carbonated drink.
Until then, my next get-rich scheme is:
Pre-mixed “Suicide” drinks. You know when you were young and you’d go to a restaurant with the serve-yourself soda fountain, and you’d mix all the flavours together? It’d be just like that, only pre-mixed, you could buy it at the store without having to buy one can of each flavour of soda!
I’d market it under the name “Homocide”. Maybe special double-case (48 cans) boxes that I’d call “Genocide”.
I’m gonna be so filthy-stinking-rich!
I’d market it as “Homicide” actually.
Yeah. Bedtime now.
A CD of the album This is the ice-age by Martha and the Muffins. 
This is similair to ianzin’s idea:
Why don’t they make 50-CD changers that I can hook up to my computer, and use the a program to put together play lists? WIth Mp3’s this has becomeless urgent, but they have had the technology todo this for years and years now and I don’t understand why it’s never been done.
Hover-chairs. For my office. I’d be top geek, fer sure…
Unfortunately, the price of water would skyrocket.
Remote controls that worked on children–complete with “mute,” “pause,” and “stop” buttons. Or maybe just over-the-counter Valium–for either parents OR children?
Children’s energy in a soft drink–I’d go broke buying it all the time, but it’d be worth it.
Hey Gatopescado (Cat Fish)
You CAN get a 69 camaro made in 01, its not cheap though.
You can buy all brand new body panels, dash, seats, carpet, wheels, and even the chassis from aftermarket dealers. Then get out your Goodwrench Catalog and pick and engine/transmisson.
…Brand new 69 camaro, make a good summer project, and it will cost at least $20,000 if you do all of the assembly youreslef.
However if you want a(brand new) 60’s Chevy Nova, Original VW Beetle, or a Ford F-100 custom, take your self to a car dealership in ARGENTINA!!! were they still make the good old cars and sell them cheap!
A lovely idea, but do you really want a gurgling, undulating ESOPHAGUSfor a drain? Eeeeeugggh.
[sub]And if there are already men having “accidents” with vacuum cleaners, just imagine the “accidents” resulting from peristaltic drains. Double eeeeeuggh.[/sub]
Too late! It’s called Jolt Cola, and it’s been around for at least 15 years. “All the sugar, and twice the caffene!” Geeks love it.
A zit vacume-it would go in, suck out all the gunk that causes the zip, clean it out, inject a healing balm, and take the redness out.
Topical menstrual cramp cream-like Bengay.
Orgasm in a jar.
Calorie free chocolate
Instant hair growing potion-I’d love to have long, thick hair instead of shoulder length, bodiless, baby fine hair.