Every five minutes, Tumblefile copies all files on your Desktop to a folder such as ~/Documents/2009-07-July/25-Saturday, prepending a timestamp (like 20090727.1645) to the filename. Meanwhile, its little window sits in the system tray. It is a way to automatically keep your Desktop cleared and files organized.
waitcond is a script to specify a combination of events using boolean expressions over various events. It can periodically grep in files, wait for the (dis)appearance of files or processes, wait for certain CPU/net/disk idle values, or wait for an idle tty. waitcond is meant to be combined with some notification tool or system.