I am looking for a video player that can play videos on my SD card with variable speed playback
Mmmm. No. At least not that i know of.
I tried VPlayer, Rockplayer, the stock player, iMplayer. None of that has control over the play speed.
If i find out I get back to you.
I can do this nicely on N900 (Maemo 5) using mplayer, but nothing on the Android side yet for fast playback of videos.