If you’re using a DSLR for video (as I’m about to, having just received a T2i to check out), your monitor options are pretty limited in-camera. Obviously you can’t look through the viewfinder, but the live view on the LCD is so small that you can’t really make much out — and the resolution is rubbish, too. SmallHD thinks they have a solution in this camera-mounted tiny HD display, but it too has its limitations.
The display part looks fantastic, to be sure: a 5.6″ diagonal (4x6x1″)at 1280×800 resolution means an excellent ppi of 270, and a ton of high-def inputs mean you’ll be getting a great image. The accessories, like an articulated arm and battery bracket, are still “projected,” so you’ll have to use the default hot shoe mount for the time being, and you’ll have to plug it in as well — that limits its practicality quite a bit.
Still, the DP-SLR is a hell of a nice-looking little doodad. At $900 for the basic and $1200 for the advanced model, however, it’s clearly for the pros out there. You can still try to find this little wireless thing, but it’s probably got a lower resolution than your camera’s LCD.