Nexave

Have you seen Nexave? It looks pretty cool plus it is also free too. "An iPhone look-alike keyguard replacement (for all Hires Palm OS devices).
Features:

Shows current time and date
Shows battery level
Shows memory state
Shows on Treo devices your own phone number and the current mobile provider
Keyguard window is transparent and can be dismissed by a down slide with your thumb or a press on the center button.
On a Treo or Centro it replaces the build-in keyguard window. For a reliable keyguard you need to set the Auto-Keyguard to "When power is turned off"."

I did a quick videocast, below, of what Nexave is all about because I think it's pretty cool.