I'm trying to empty my trash, but it says that the file I'm trying to delete is in use, and it gives me the option to hit continue or stop, and when I hit either one, it doesn't go away. The item isn't open anywhere. How do I get rid of it?
If you know for sure you don't want whatever is in use, just go to the Finder menu and hit Secure Empty Trash (if it's greyed out, create a dumby file and put it in the trash...there needs to be something in it).
I notice that happens a lot, especially after viewing videos in QuickTime. I downloaded a little program called cocktail. One of the tabs let's you easily force empty the trash without having to restart your computer. In cocktail I believe it's systems/misc/force empty trash.