PopClock - this application is a clock which works like a screen-saver. While the app is working, if you leave your mobile phone be for a few minutes, the clock appear in your screen. Please touch the clock, and it will be hidden at once. Time from disappearing of the clock to the next display can be set by pushing the option button
BlackMe is a tool that turns the screen off while you don't need it.
You can use it while logging gps data (for example with WMMiniGPS), when you connect your device to the desktop to sync/recharge it, when you're listening to music with an mp3 player, etc...The best method to use this program is to associate a button to it (through Settings->Buttons)