I was wondering if anyone had any pointers they'd like to share? This is a great device, but since we're all what you could call early adopters its still something that could benefit from users sharing their own tricks.
Of the top of my head:
Audio/Video sync problems:
I've noticed occasionally I have sync problems with audio, generally on videos with variable bitrate audio. I use VirtualDub to quickly recode these because it allows you to copy video (or audio, or both) allowing me to recode only the audio (using a constant bitrate) typically taking under a minute.
Obtaining subtitles:
Typically with foreign movies I'll obtain subtitles using subscene.com although opensubtitles.org is also helpful (both typically use the srt format). The few times I've been unable to find existing subs I've used VobSub to quickly convert DVD subs into the srt format.
Quickly recoding problematic video formats:
VLC media player (a great open source software video player) can read most any format which alone is great, but it can also save/convert into a number of other formats, often at better then realtime. When I have a format problem I typically use VLC to convert the video using the mp4 profile (which so far seems to be the fastest) and a minute or so later I'm happily able to watch the video.