This is AWESOME! If you leave your iPhone or iTouch in your vehicle, and if you have IOS 5.0.1+ on your device, and have WIFI-Sync turned on, you can sync music and videos to it wirelessly from inside the house! (as long as it is in range of your wifi)
I can add/change songs, videos, playlists, and then press the sync button to my iTouch or iPhone thats been left connected to my pioneer deck, and it'll sync wirelessly while I'm in the house and my truck is outside! How awesome is that! No longer needing to bring the iTouch in! I just leave it, if I find a cool tune or vid, I just add to iT