Glad it worked. As Jon noted you can install a hack to let you completely power off the 500. That will keep the battery in shape for months, but it does take a while to start when you first restart it.
If you don't want to use the hack, you can also just press the reset button, but then do NOT turn it on afterwards, just put it away. It will cold boot next time you turn it on.
Make sure to sync it with the computer first, or you can lose your bookmarks. You'll need to resync it with the computer to reset the time after you wake it up.