Should I partition?

Hi everyone,

I know there's been some posts on this before, but wanted to ask more specifically with regard to my own situation...

I have to do a complete wipe and reinstall of Leopard (archived and installed from Tiger and ended up corrupting some OS files). I didn't even set up Time Machine yet so I was doing manual backups. I want to avoid some of this mess in the future so when I wipe I am considering creating two partitions, one just for OS and one for my apps and data -- so for future OS upgrades I can just wipe clean and install. But I was wondering...

- Is there any good reason not to do this?
- If I do do this, how much should I partition my OS drive to be? I'm running a Core 2 Duo MBP, 2.0ghz and 2gb of RAM with a 120gb HD.

Thanks guys, and any thoughts you have to contribute are much appreciated.