If you're using Gnome, alt+F2 opens a dialog box to run programs. The program is "googleearth," so that should work. I think its in the Gnome menus somewhere, I just never really use those.
As for the video acceleration, I don't know much about the Intel graphics cards, but as far as I know, the drivers are built into to Ubuntu and they should be enabled by default. Maybe the card just isn't that powerful.
It also might be the program, because I have a Geforce 7900GT KO Superclocked and it's a little choppy for my liking. I'm willing to bet that with the actual release (since this is a beta) it will have improved on performance.