I also stayed with CS3 because Linda has CS4 Creative Suite on her computer and I didn't think it was all that much more powerful for the Photoshop application. However, I suspect that CS5 will require Snow Leopard which means I'll have to upgrade the operating system to get it. It's all a trap

. First, Apple and Microsoft create new operating systems and beg you to upgrade and then the applications developers realize that it's much more economical to create new applications for only the latest operating systems. And then Apple and Microsoft do it all again.
And let's not forget the hardware side where the new operating systems only work on the latest chips so you have to throw out your G5 if you want to run Snow Leopard and CS5. It's a vicious cycle that only works if we decide we can't live without that newest feature in the application. Ultimately, we all are forced to upgrade -- both hardware and software. The question is always when is the optimum time to do so.
Jim