I just came across this tonight. This is a really slick application. Different than My Phone. Can sync any and all documents and photos from your PC to your smartphone wirelessly (OTA). Has a desktop application and a CAB file for Windows Mobile. Several different plans to choose from. I installed this and sync'd my entire My Documents folder from my PC (that takes awhile). The same files are now available through the application on the Treo. For a test, I created and saved a new file in my sync'd folder, and then picked up my Treo and it was there for the viewing.

Pretty cool. Check it out.