Just stumbled across this today: if you open the Clock app (shows time, weather, and alarms) and then let the screen timeout or hit the lock/power button, the screen and soft keys will lock and darken, but any physical key will unlock the screen without requiring you to do the normal unlock slide. You are then taken back to the Clock app with the screen unlocked and active. I tried to do the same with a couple of other apps (open app, hit lock button, then try to unlock) and I was always forced to do the lock button and unlock slide sequence. I Googled a bit and searched this forum to see if this had been reported on other phones, perhaps this is new to 2.1? It would be nice if this had been restricted to just the lock button, I think it would be fairly easy to accidentally touch the trackball while the phone is in your pocket, which would unlock the screen.