This is something that a lot of you have been asking about and there was never a good answer, until now! Maniac's Smartphone Tools offers a handy automatic keylocker for your Smartphone. It works on both Windows Mobile 5 devices and Windows Mobile 2003/SE and has lots of configurable settings, including an ignore list, device lock (instead of just keylock), and different timeouts for the home screen versus an application. If that wasn't enough to get you interested, it also offers a simple screen saver that shows off the time and the number of missed calls / emails.
The program is "donation-ware", so please remember to give whatever you can if you enjoy using Maniac's application.
__________________
"I have no special talents, I am only passionately curious" - Albert Einstein