I am planning on doing this myself. However, not with unbuntu. 

From what i understand, while it is Unbuntu makes it easy to install, there is a trade-off that you toil with later. For instance,  Unbuntu has *big problems* with audio programs (programs which are beyond simple file players).  
This is NOT the case with Debian-- which once up an running, is pretty smooth when it comes to sound apps.  Not to mention Debian has a really, really easy way of updating and installing apps. 

So, check into this question of which Linux for audio, further.

- Andrew

"If we cannot discuss
We cannot think
If we cannot think 
We cannot invent" - Frank Little


>Subject: [PD] OT dual booting OSX/unbuntu
>ok, i am going to try to dual boot OSX with ubuntu linux.
>opinions please