Bigasoft iPhone Video Converter, the professional AVI to iPhone 4S Converter, is specially designed to help iPhone users to enjoy all kinds of video and audio on iPhone 4S /4/3GS/3G. It can easily convert AVI to iPhone 4S MPEG-4 or HD H.264. Besides, it also support converting other videos including WMV, ASF, MKV, MPG, VOB, MTS, F4V, WebM, WTV, 3GP, FLV, MVI, BIK and more to iPhone format for playing on iPhone 4S , iPhone 4, iPhone 3GS, and iPhone 3G. Moreover, this powerful AVI to iPhone 4S Converter is equipped with advanced video editing function like merge videos into one, trim and crop video, adjust audio volume, rotate video, add audio track and subtitle for video, increase artistic effects for video, add image or text watermark for video, split video, and more.
the following will take converting avi to iphone 4s as an example at http://software-iphonetools.blogspot.com/2011/10/avi-to-iphone-4s-how-to-convert-to-play.html