Run CS3 and 8 at the same time on mac?

I want to download a trial version of the CS3 and run it, at the same time, as
my existing Dreamweaver 8 on my G5 Mac running 10.4.10. (It is NOT an Intel
Mac.) There is a 30 day trial and this way, in the downtime between projects, I
can test out and use the CS3 version and make sure it is stable on my system,
learn to use it a bit, set it up the way I would want it, but always be able to
cut back to 8 in a pinch if I have mission critical work that must get done. I
know 8 like the back of my hand and know nothing about CS3 version, so I like
the safety net of being able to run them both.

Any issues with this? Is it possible? Will it break anything - like with my
stable and running CS2 apps and Acrobat 7?

great.. thanks so much!

I did not expect to run them at the same moment, just be able to have them
both on the system and be able to go back to 8 if needed.

also, thanks for the heads-up about CS4, I might hold out then.