When I had Snow Leopard I had the Google address book sync enabled and I somehow managed to put a 'sync' icon in the menu bar.
If I remember correctly I added it from the "old" synciSync
application (unsuccessfully trying to sync with a Samsung phone).
Now in Lion I still have it and it allows me to manually force the update of my Google address book, but I can't find how to obtain it as the synciSync
app seems to have disappeared.
This article here describes the situation of iSync in more details