Zerospan needs a good one-sentence blurb to explain what it is. Here are some suggestions - please add you thoughts, or try your hand at crafting a new one!

Zerospan is a free application for Mac OS X that can "bridge" any two computers via Zeroconf (aka Rendezvous or Bonjour), allowing you to share iTunes, iChat, file sharing, SSH, and more.

Zerospan is a free application for Mac OS X that lets you connect to Bonjour services on a faraway computer, allowing you to access iTunes, file sharing, SSH, and more.

Zerospan is a program that will let you easily connect to another Mac over the Internet and use iTunes, etc.

Zerospan lets you connect to another Mac and use many apps.

Zerospan lets you connect two computers as if they are on the same network, except when you open it on one of them and get a huge error dialog that says "An unexpected error has occurred during execution of the main script" followed by a bunch of unreadble tech gobbledygook that you won't get any help with on this site's blank troubleshooting page.