Spanning Sync v1.0, an application that provides two-way synchronization between Google Calendar and Apple iCal, has launched after seven months of development - including a four-month beta period. As The Unofficial Apple Weblog noted, Spanning Sync also syncs between multiple Macs and Google Calendar accounts, with iSync-compatible devices like iPods and mobile phones (iPhone too when it's released), and with Google Apps for Your Domain (Google's hosting service).

It is an Apple-only application, so many people (myself included) can't use it. But it's an excellent example of two trends which we're tracking closely here on R/WW:

1) offline/online sync functionality

Spanning Sync founder Charlie Wood told me:

"I believe in a hybrid future where desktop/mobile applications serve as front-ends to hosted applications and work even when a network connection or the hosted application itself is unavailable. Such hybrid applications will be powered by transparent synchronization, which is a hard but not impossible problem."

It'll be interesting to see whether the big companies (Google, Apple, Microsoft, et al) will offer more sync functionality over time. At the moment it's innovative startups like Spanning Sync, Morfik and Sharpcast - and some big companies too, like Adobe - which are leading the way.

2) Integration between web companies, in this case two biggies - Google and Apple