quote:
Originally posted by Harr1l
Symbian phones allow user to install native apps (not java) like AgileMessenger which is very good instant messaging program. You can also install many other apps like screensavers, google maps and some games too (also N-Gage games will work).
You can do all you mentioned above on the Java platform.
I have seen all of what you mentioned as a java app

Example:
mig33 - Instant Messenger
Ruza - Something like a screensaverp
J2meMap - Google map java application
Zelda Mobile - One of the many mobile java games 
As you can see, many stuff are available for the java platform (especially if your phone has MIDP 2.0 which the K800 has, and every new phone in general).
You should get a symbian phone however, if you want more advanced features like PDF document reading.
If you decide to get a symbian phone, get a sony ericsson symbian phone