Good writeups on various functions of the 770.
The 800 looks very interesting, with doubled ram size, a faster processor and SD instead(Or rather with) the RS-MMC slots means that most of my problems with it seem to have probably been fixed.
Personally my 770 gets used for a variety of things...
PIM with the GPE suite of tools
Portable game player (Tuxpuck and Supertux, along with occasional Doom when I am bored enough)
VNC viewer. This is very handy for me as I use it to set levels for shows I design without having to be at the mix console, can't understate its use to me.
Overall swissarmy toolkit. Going to put a Ethereal/Kismet/Whatever else I come across for disagnosing when I need to.
Note taking(Especially during production meetings- useful to keeping me organized)
And last, book reader, or more specifically I keep the scripts I am working on on it so I always have access to them.
Freakin flexible thing, using the thumb keypad for typing I am getting decent in taking notes in notes, I was using an annotation program for it.
Speaking of annotation, the doubled ram and faster processor means that will become a much better option for me I believe so I can write notes directly on scripts I am working on. Extremely useful. Had problems with larger PDFs before, so this should be great. I will be heading out as soon as I can afford one to get an 800, probably use the 770 for remote control purposes after that, another things i use it for on occasion. Nothing like forgetting your remote to your laptop and using the web interface of VLC to remote control it, though the interface still needs a bit of work