@hammerv2 You might be surprised to learn that Ubuntu Intrepid is the mothership of all memory hogs. If you can, try disabling many of the window effects. You might not notice, but there are fade-in-fade-out effects, slides, etc that chew into performance, even if they're not currently your prime focus. From what I've seen in Dyson, it's basically an OpenGL window layered on top of everything else, which means Ubuntu's still drawing the desktop and panels.
@lobo235 That's X.org for you. Apart from upgrading your machine, there's no real way to get around that.