sorry that was quick.. i saw your post while scanning back for a different post..
I burned a copy of Ubantu's Fiesty Fawn release a couple of weeks ago and it seemed to run great on my gateway mx6445. I didnt play with the wireless connections to see if i could get it to connect, as it was really just to recover some files from my crashed Xandros distro before a re-install.
Installing linux distros typically gives you the choice to either
A. take over a drive (ie wipe it and install the distro
B. Add a partition and dual boot ( i think the most common, but you need to have a free blank partition
or run from the live CD.
It was pretty clear when i tried FF of how to do it to not wipe any data.. but double check in their forums if you have any questions..
I tell ya.. Fiesty looks great.. and compviz is a very slick interface..
Let me know how it goes (lol or if youve already done it)