Hi Terry,
Seeing as no one else has responded...
I'm using Windows XP and I have a directory called Arduino. In there are all my project folders and I unzip the different versions of the IDE into their own sub directory. I have versions 0.21 through to 1.0.4, but I don't have any of the 1.5.x so I don't know if the same process will work for them.
I also ignore the convention and I put my library files within the libraries folder within the individual IDE folders. That way I can still run (if I need to) 0.22 and 1.0.4 without library conflicts.
I have created short cuts on my desk top to the different Arduino.exe's.
Hope this helps.