Aiptek V10+

This micro-projector works with a range of portable gadgets: cell phones, DVDs, and video cameras. It comes with speakers and two gigabytes of built-in memory, which can be extended up to eight gigabytes with its internal SD/MMC memory card slot. This allows images or a presentation to be loaded onto one single handheld device. The built-in memory allows a user to share content by recording it directly from another device while also projecting it. The V10+ supports AVI, ASF, MEPG4, and JPEG file formats and displays images with a resolution of 640 X 480.

3M MPro110

This projector is designed more for business users who don't want to lug around a heavy projector. It's particularly good for PowerPoint presentations and can cast a 125-centimeter image from just 1.2 meters away, with a resolution of 640 x 480. Unlike other micro-projectors, the MPro110 comes with its own miniature tripod, which is handy if you don't want to balance the device on books or hold it. On the downside, it doesn't come with speakers or an audio-out socket.

Adapt Pico Projector

The Pico Projector, made by Taipei-based Adapt, features a Video/VGA cable input and no speakers, so it also seems that it is aimed at professional or business users. Under the hood, however, the Pico packs more punch than its competitors, offering 17 lumens--the perceived intensity of light--compared with the 10 lumens offered by the other two projectors. As a result, the image appears much clearer in lighter conditions, or at least requires less-dark conditions for viewing. The Pico will display 125-centimeter-wide images at a 640 x 480 resolution, features one gigabyte of built-in memory, and will run for about an hour on its lithium-ion batteries.