Chrome Version 7.0.529.0 canary build has the Labs feature “Instant” which Makes the address bar load urls as you type.
Update: about:labs has moved to about:flags in Chrome
For the sites, that you have visited already, you will see the sites directly loading, before you press enter (after typing the url).
If you want to try this, Download and install Chrome’s Canary build (auto updated every week).
Disclaimer: Google Chrome Labs is a testing ground for experimental features that aren’t quite ready for primetime. They may change, break or disappear at any time.