On my Windows 7 puter I have: Firefox / IE / Google Chrome / Safari

On my Mac I have: Firefox / Google Chrome / Safari / Camino

I have an AOL email account which I can access without problems from any of these.

I've never had the slightest problem with clashes, and find it useful to have different browsers for different log-ins (such as Yahoo & Gmail accounts) even though they all do tabbed browsing.

So go for it!