Here's a simple overview on how to play FLV files on the Official VLC for iPad app.
- Download VLC for iPad from app store free
- Plug iPad into itunes, Select iPad, goto Apps Tab, Scroll to bottom (File Sharing).
- Select VLC
- Click add. Locate any flv files you want to transfer and rename them to end in .AVI
- Add them.
- Open VLC and enjoy FLV on iPad. (Seems a bit more choppy than the XVID movies i tried which went really smooth.)
Pretty simple, right?