I would like to share an excellent guidebook from Adobe for encoding videos for the Flash platform:
Adobe Systems Inc. (2010). Video Encoding Cookbook and Profile Guidelines for the Adobe Flash Platform. Retrieved at http://www.eventsadobe.com/cookbook/ on September 4th, 2012.
This 64-page white paper covers basics on encoding videos for the Flash platform and provides helpful suggestions on how to set encoding parameters in order to achieve optimum video quality for the target size, resolution, bandwidth, platform, etc. I hope it will be helpful for us in encoding videos for Vialogues and NLT. You can download the white paper either from the link provided above (requires quick sign up) or in the attachment.