you could check the Megacast, it supports mp4, 3gp, avi, mkv and all the other file formats..it does the transcoding on the fly on the device and with no delay or anything...
I started using this new app called megacast, it transcodes the video on the fly on your device and supports avi, mkv, 3gp and all other video file formats, so i don't have to bother with changing the format myself.