On Palm devices, you could set a power-on password, and while the phone prompted for the password it could display a message (i.e., saying who to call if the phone was found). Once Palm made it so you could enter the password while on a call, it was great.

On WM, there seem to be two bad options:
-- Set a numeric PIN: This doesn't take advantage of the Treo keyboard, and you can't figure out how to display a message to someone who finds the device. It's also not clear that this secures ActiveSync.
-- Set an alphabetic password: Windows Mobile's requirements for this password are completely impractical (must be really long, a mix of uppercase, lowercase, punctuation -- if they were available, they'd have required a dozen Egyptian runes as well).

The ideal solution would be one that allowed one to set a short password that locks after 3-4 failures (with a longer recovery password), and displayed a user-settable message for anyone who finds the phone. Integration with the SIM unlock would be even cooler (so that it wasn't necessary to enter two passwords on a hard reboot), but I'd take just about anything besides the current system.

Anyone have any good suggestions?