Just to say i no longer require an answer, i have found a more than acceptable quality conversion process from large AVI/MOV files to one the berry can deal with..
I believe this to be a better solution than any I have seen out there so far, the quality is brilliant, the simplicity is good, and the time taken to convert is very realistic even on a slwer pc. though perhaps I have missed some guides.
Anyway in case anyone wants to try it.. Im back to using the same program I used for my treo, but with a few different options the bb now displays the movie..
I use PocketDivxEncoder
1. open file
2. select "pc" as template
3. "change" output dimensions and reduce to 320 or 240 which ever is biggest.
4. reduce video quality to "37" ie 598kbps
5. set audio auality to "7" ie 128kbps 44khz 16bit stereo
6. click "advanced options" and tick "xvid"
7. if you're in a hurry also deselect "vhq" it makes little difference anyway to the quality on this size film but adds maybe 1/3 time.
8. untick "audio normalisation" if going to use headphones to listen to

(though technically its audio compression not normalisation lol. but hey what do i know! lol!)
Click encode

then upload the file AS IS without modification using the USB disk mode thing or making sure the media manager doesnt recompress/modify it, a film will be 4-500mb, plays perfectly smooth with no skipframes on my 8320 with minimal compression artifacts. woop woop..
Would love to hear feedback from anyone else trying this method who has had "other" methods they've become familiar with, to see how you think it compares.
The bitrate i used for video has not been fine tuned, its the first sensible level i found low enough not to skipframe and high enough not to look crap, but im not sure how much fine tuning you could do to achieve a good vid on smaller space, or even if you could raise it a bit to get rid of some more artifacts without any skipframes. the software gives you a good estimation of file size so you could easily drop this lower to make a vid small enough to fit the space on your SD card
