You can use iSync Uninstall 1.0 to remove files associated with the use of iSync Beta software. This includes the main application as well as libraries, frameworks, installation receipts and user-associated files (Preferences, SyncServices data, etc...).
iSync Uninstall 1.0 will not remove any other personal data files. Address Book, iCal, and Palm Software are left as is.
Note that subsequent releases of iSync may require you to remove iSync Beta before installing a later version.