Mac trick: change Time Machine backup interval
If you think Time Machine is backing up your Mac too often, you can customize the interval between two automatic scheduled backups. I found that trick on MacYourself.
Open up a Terminal, and change the value, in seconds, of the interval (here 7200 seconds == 2 hours instead of the standard one hour):
sudo defaults write /System/Library/LaunchDaemons/com.apple.backupd-auto StartInterval -int 7200
Update: This doesn’t seem to work on Mac OS X Lion, although it worked in previous versions (like Leopard). Till we find a good workaround, Thomas, in the comments, suggested looking at this nice little utility: Time Machine Scheduler.