On the Mac, can I have both unity 2.6 and 3.0 installed at the same time?

Questions & Answers
1

I'm not ready to upgrade my current project. However, I do want to play around with all the 3.0 goodness.

3

simply rename unity 2.6 and type "unity 2.6" instead of just Unity so when installing it will not overwrite your older one

so u may still select the same download area :)

Source: i did it myself

2

Install them in different places

4

http://answers.unity3d.com/questions/20011/how-to-install-two-versions-of-unity-on-one-machine