I am exporting videos for embedding in enhanced epub files (which can be viewed on iPads and Nooks). M4v is the recommended mime type (mp4s have issues on some devices). However, the only option I see that allows me to do this with Premiere 5.5. is to export as MPEG BlueRay which results in a ridiculous sized file - all I need is something 480x270. For this 3 minute video, it should be around 50mb or so. A bit rate of about 1,000bps is ideal.