I'm in the process of converting short clips for use on mobile versions of web sites that can be played within the web browsers on Blackberries, iPhones, and the like. The clips are about 30-45 seconds long and are under 3.4MB.

I have tried just about every size/aspect ratio/bitrate combination of the mp4/h.264, 3gp and psp export options in Adobe CS3 Media Encoder without success. They will all download as random 'gibberish' characters in the phone browsers (including on my Blackberry). I can manually move the video files to the phone's memory card via usb, but only the audio plays back - the video is a black screen.

On the PC, the browser prompts to download the file instead of playing it (as if it doesn't recognize the mime type/file type). The files play just fine in Quicktime and VLC.

I spent all day yesterday scouring the web for information without any results - has anyone had any success with this?

Dan, have you embedded the video in the web page? Or just linked the video file to a text link?

As far as good format, I'm afraid you will have to forget CS3 and go to a dedicated encoder like MPEG Streamclip or HandBrake, and use the "iPhone" preset. Will that play on all phones... probaly not. I tried a zillion formats myself until I found something that plays on my BlackJack - it's Divx. The iPhone presets won't work on my phone, and probably the Divx won't work on other phones. It's a jungle out there...