My iMac is a first gen 24", bought in 2006. It has served me well, but has been running kind of slow lately. I've never reinstalled the OS, and I'm currently running 10.5.8. It has a 2.16 GHz Core 2 Duo with 2GB of 667 MHz DDR2. I've recently wanted to do a couple of things that require Snow Leopard, and I thought I might upgrade. Will Snow Leopard speed things up a bit? Maybe I should do a "clean" install? I'm scared to do the clean install because of all the time I've put into iTunes, iPhoto, and various other programs. I should add that I do have a time machine backup drive. Any advice?