What is the best way to clean up a system that is getting over a year old and has had a lot of files created/installed/deleted in that course of time? I have pretty much 90% of my hard drive filled and that would be a much higher number if you counted the space that spilled over onto the external. Point is I have a lot of spread out files and need everything to come together and work smoothly. Of course on a PC I would simply defrag. What do you do on a Mac when it gets slow? Also... Firefox has been pissing me off lately. It will stop intermittently every 5-10 seconds for about 2-5 seconds and the rainbow wheel will appear. This is getting annoying. This is my main problem. Any suggestions?