Running on a laptop with external monitor (as dual monitor). No major problems with the graphics or wifi or anything else.
I looked into doing that for my Ubuntu 7.10 laptop, since I have an extra monitor lying around, but it goes with me on trips so it must be able to do single monitor mode too.
All I could find on the web, though, said such usage was flaky at best and downright hard to setup (for 7.10).
I'd be interested to see if they improved that for 8.04
Ill give it a try a few times tonight and let you know how things go
I also had the same panel problem where they will move to the single monitor but not move back when the other is reattached.
I hear the next version (intrepid ibex) will be focused on mobile computing so maybe some of these issues will be addressed.
The main downside of this setup (other than the rebooting thing) is that it makes it impractical to unplug my laptop and move around when I feel like it.
I'm also interested in seeing what happens under Hardy.
The latest RandR added support for that, which appears to have gone in about a month before Ubuntu 7.10. I haven't tried it, but it's a safe bet it's better now. Whether it's good enough for your setup, I can't say.
I used EnvyNG to get the right drivers and it worked like a charm, I did have problems trying to install the driver directly.
Good luck!
Which is nice, because video drivers were the only nontrivial thing that didn't work for me in Gutsy -- the free nvidia drivers don't work at all with my T61p, and the version of the proprietary driver in the repository was complete crap.