Ok. Getting frustrated because i've tried everything. Keep in mind, I've been using linux for quite some time as my desktop and this is my first attempt and such a task.

I have an IBM Thinkpad T30 laptop with a Radeon 7500 mobility. Here's what I want to do:

Span my desktop across both the laptop's LCD and the external monitor I have plugged into the back of the laptop. Windows XP is capable of such a task. Not sure if it's doable in linux. Currently, if the external monitor is attached. I get mirrors desktops.. in other words both screens show the same thing.. but i want to extend my desktop onto the other monitor.

Doable? If not, is it possible to have each monitor show a different desktop?

Works just fine in linux. I do it all the time. Course, I use an nvidia which has driver specific options for doing so. You'll have to go look up your Radeon and find the driver specific commands and set up your XF86Config manually to allow dual monitors...

Ok Where am I supposed to look this up?

wherever you download your drivers from. Drivers have "readme" files with instructions for the features.