As a previous PalmOS user I really liked SplashID as my place to keep secure information. As a PPC user I found the crop of security apps ok but not as easy to use as I would like. So after a year of waiting I finally was able to make the switch to SplashID for PPC.
Splashdata www.splashdata.com is working to have all of their apps up for all platforms: Palm, PPC, MS Smarthphone, P800/P900 & Series 60.
One great feature about their apps is the registration code works for the registered users on any of their OS platforms. I moved my codes from Palm to PPC and if I had the multiple personality thing going I could run Palm & PPC and run both version on their respective machines without issue.
If you want a siple interface that secures your data give them a try. Now the secure app comparison can be updated to include SplashID.