Now that second-generation pico (i.e. really tiny) projectors are hitting the streets, you can pick up first-gen models for a song.
Witness the 3M MPro110, on sale at Newegg for $149.99 shipped. It's a refurb, but given that it sold new for $359 just 10 months ago, you gotta take a look-see.
The impossibly small MPro110 weighs 5.6 ounces and measures 0.9 inch high by 2 inches wide by 4.5 inches deep, meaning you can literally stuff it in a pocket.
CNET hasn't reviewed the MPro110, but be sure to read the reviews at Gizmodo and PC Magazine. The chief complaint lies with brightness: you need a pretty dark room to enjoy the view, and you can't get an image much larger than 20 inches without taking a brightness hit.
Of course, if you're running a photo slideshow or watching a movie, 20 inches is way better than the source device's little LCD. The MPro110 may not be a suitable replacement for a boardroom projector, but for fun and leisure, it's pretty sweet.
You can learn more, and see the gizmo in action, in the above video (which is a little cheesy but very informative). Still more info is available at 3M's product page.
Newegg doesn't specify the warranty, but assume 90 days (and call or e-mail them if you're concerned about it). I don't really have a need for one of these, but I'm salivating over that price.