Portable media players are great for personal use, but aren't so helpful for sharing the fun -- with small screens and at best tiny speakers. And even laptops are not great for viewing by more than a few people.
What you need, then, is your own pocket-size projector like the second-generation 3M MPro120 Pocket Projector. This does indeed fit in your pocket at 4.7 x 2.4 x 1 inches, and 5.6 ounces. It's now available for around $299.
The MPro120 throws an image up to 3 1/2 feet, or from 8 to 50 inches diagonal. With brightness settings for 10 to 12 lumens it's not going to overpower sunlight, but it's bright enough to see in a lit room. It uses an LCOS imager with LED light source, rated for 20,000 hours (so there's no lamp replacement).
The unit displays at VGA resolution (640 x 480), and includes a built-in speaker. You can hook up to a laptop (with the included VGA cable plus audio) or to analog video (with the included component A/V cable; component cables are available separately). And you can display from iPods (also including the touch and iPhone) with a adapter separate cable from Dexim (see previous post).
The similar line of DLP-based Optima Pico Projectors now includes the PK-102, with 4 GB of internal memory to store photos and videos at around $249. It's speced to throw an image up to 8 1/2 feet (5 feet diagonal), with a display resolution of 480 x 320.
But who needs a separate projector? The Nikon COOLPIX S1000pj 12 MP digital camera includes built-in projector at $29. It throws a VGA-resolution image of up to 40 inches a distance of up to 6 1/2 feet, at up to 10 lumens.
See my HDTV Gallery for more on portable projectors
Find the 3M MPro120 Pocket Projector
and Optima PK-102 Pico Projector on Amazon.com