We last mentioned Picnic when the beta was released in June; now Objectpark software is shipping version 1. Picnic is a utility designed to allow you to synchronize folders you specify between two Macs on the same local network. By using Bonjour it requires little or no setup.
Unfortunately, I see two major downsides to Picnic. First, it seems rather expensive. Each machine/user requires a license which are $29.95 each (though there are discounts when ordering multiple licenses, e.g. $55 for two). Compare this to the similar Martian Slingshot at $29.99 for use on all your personal computers. Second, it only works over a local network and not the Internet (though I suspect you could hack it together with Hamachi or another VPN solution).
A demo of Picnic is available for download.