Go into my computer, click add and remove programs towards the top, and uninstall programs you no longer need. If you can't free up enough space by doing this consider adding a second hard drive.
1. delete cookies 2. delete temporary files 3. defragment your hard disk monthly ones 4. delete recent documents 5. delete history 6. avoid installing unwanted softwares. 7. run desktop cleanup...
MySpace itself is, yes - however I have had my virus protection identify several of the rotating adds (not from MySpace, but served through them) used at MySpace as spyware / viruses.