The new Parallels Desktop 3.0 for Mac can sync your iPhone using iTunes for Windows XP and Vista while running inside Parallels. The updated version is available for free to all existing users of Parallels Desktop 3.0.
Paralles vs VMWare Fusion vs Boot Camp
Parallels allows Mac users to run Windows XP or Windows Vista and Windows Programs simultaneously just like other Mac programs without requiring a reboot like Boot Camp does. Link.