external monitor on old Dell 700m?

Hi -- linux noob so forgive me.

I've installed 10.04 on a dying old Dell 700m, in hopes of using it as a home theater device. Install seems to be working fine, much faster and more stable than Windows XP, but I cannot send output to an external monitor. VGA cable works fine, external monitor recognizes other computers fine, but with the 700m it gets no signal.

It appears that the 700m doesn't have a Fn hotkey to switch monitors like every other computer out there -- the only way to switch monitors in Windows was to use the Control Panel. The linux monitor setup isn't recognizing or detecting any monitors, although the laptop's own display works fine.

I've found a handful of workarounds for this w/older Ubuntu builds, involving editing the xorg-conf. I gave one a shot and it seems to have screwed up all display on the laptop for good -- after it reboots it goes to a blank screen and I have to do a hard restart. I'm fixing that with a clean reinstall, that's no problem, but I'm cautious about editing xorg again. Any advice?

Possibly relevant info:
Dell Inspiron 700m, 1.6GHz, 512 mb RAM, VGA and USB outputs, running Ubuntu 10.04