Spanning Sync: gCal and iCal play nice

One of the more annoying aspects of gCal is you just can't easily update any of your calendars when you're offline, as far as I know. And with iCal you can't update your calendar online. Spanning Sync seems to solve both problems by syncing all the sets of gCals and iCals on whatever computers I set it up on. After the 15 day trial it costs $25/year or $65 as a one time purchase, but it seems to be working really well and I might purchase a license if it continues to function as it has so far.