Ok, I am new owner of an N800, and have gone through the basics and many of the suggested web pages (not all, yet). One of the questions that keep coming up in my mind when I see all the code written for the 770, will it work for the N800? Are there hardware differences which require a recompile of these applications to work on the N800, or does it just work (with the right dependencies fulfilled). Bottom line, what do I have to know or look for to know if a piece of code will work for the N800 when it was developed for the 770?

A 770 app stands a good chance of working on the N800 - the 770 hardware is a subset of the N800 hardware.

The reverse is not true however.

Well, while the 2006 and 2007 OS's are binary compatible, differences in OS, may make it so it does not work on the n800. Very few apps fall/fell into this category though, most have been fixed.

If your to concerned, search here for the app and see what people are saying before installing it... If you cannot find anything, make your own post and ask about the app?

also, you should set up your device for dual boot.. that way if you install something that borks it all.. its just your card install and your flash is nice and toasty secure