I still consider myself a newbie even though I've had my N8x0 for almost a year now...because I'm still learning all kinds of new things I can do with it. I love it.
I just installed Ubuntu on my PC and am learning to really love it also. Here is my newbie questions. What cool advantages do I have runny 2 different Linux versions. Are there common application I can run on both that sync? Or anything I can really get both working well together?

I don't know what application you want to sync, but if you run x11vnc on your tablet and a vnc viewer on ubuntu, you can control your tablet using the desktop. Works with windows too.

Install openssh-server on your Ubuntu machine and sshfs on your tablet, and you can mount your Ubuntu drives on your tablet as if they are local! That's pretty cool. Even cooler, if you get a router that can do port forwarding, you can mount your Ubuntu machine's drives on your tablet anywhere you can get Internet. It is encrypted and secure, too!

Also, Ubuntu has a built-in Remote Control feature; it works with the tablet's VNC viewer, so you can control your desktop with your tablet; the opposite of what sarahn describes.

i have a specific user-case scenario: a desktop computer with ubuntu linux is running two programs through wine: hansaworld and macister. what would be the possibilities to access those programs via the n900? a remote control session as described above sounds reasonable, is it?

I've run wine apps in a remote shell session to my desktop (using ssh -X) before, with some success, on my N800, although I had issue with the on-screen keyboard. I expect with a real keyboard, as with the N810 and N900, it could work out OK.

If they are running on a Ubuntu Linux/x86 computer and you an remotely log in on this computer e.g. via VNC this would work. You cannot run Windows/x86 applications on Linux/ARM though. Even if you take WINE into account the programs are compiled for different architectures. Maybe Mono would work, I'm not sure. Java should, provided the official Java (e.g. Sun Java 5.0 or 6.0) runs on Linux/ARM.

As fnordianslip said, the physical limitations of the tablets can be a bit annoying sometimes. On my N800, using the virtual keyboard in VNC leaves very little viewable area.

But yes, VNC works great for using remote apps. I would recommend using VNC instead of ssh -X because if you lose connection with VNC, your work is still safe on the host computer. When using ssh -X, a loss of connection means the program closes and your unsaved data may be lost.

I speak from experience. I've run MS Word on my N800 over ssh -X from an Ubuntu computer using Wine... It's all good until the connection drops. Then boom. All your changes are lost.

The only problem with Ubuntu's VNC server (Vino) configuration is that you must log in on the host computer locally in order for the VNC server to start. If you need to log in remotely, you have to SSH in and then run x11vnc as root to see the login screen. It's a real pain.

Just use NX instead of VNC. Its much faster and supports resuming.

I run the GPE PIM applications on Ubuntu and the N810. They can be synchronized because they use the same DB, sqlite, on both platforms. In particular I run GPE calendar, contacts, todo and timesheet. On the tablet I also run erminig which syncs the GPE calendar with my Google calendar. There's also an application called notecase which run on both. It's also file compatible on both platforms. I like it because it allows me to password protect notes files so I can keep sensitive data in them.

I have read over what you guys have recommended. I am relatively new to networking, vnc, remote conenctions, and using ssh connections. i am a complete linux user(although i know how to use rdesktop with windows as my roomates wont give it up), but i find myself stumped in doing the simplest vnc connection.

i am using tightvncserver(and xtightvncviewer with the other desktops i use) to see eachother. i am able to get the viewer software to show the 2nd background( IE snoopy:2), but only on the machine i am running the server on. (i know thats not an issue that has to do with the n800 but help is appreciated).

now on the n800, i have vncviewr installed,and i have x11vnc as well as sshfs. i am only trying to get my handheld to remote into my ubuntu machine(i intend to use it to play media and such while i am at work[which is a calcenter with wifi]).

im sorry if this doesnt make sense. feel free to reply with ?s and i will answer to the best of my abilities