1) Set your search engine to Google (if it isn't currently)
2) Remove the search bar.
3) Press ctrl+k (cmd+k) and start typing. You'll be searching on Google's site, by far the best search experience with Google Instant on.
The only downside is that you need a reasonably fast, low-latency connection for it to work well.
 Fine with decent Internet service, but what a downside it is on a lesser connection. The ~0.5-1 sec delay was unbearable on a 3Mbps DSL connection with average latency.