If you are like me, you do a lot of searching every day. Not just Google, but IMDb for movie info, Amazon, TED talks and even TUAW. To help out people like you and me, Cynapse Software has introduced a nifty utility called Phlo. It provides a pop-up search field that be assigned to a global hotkey and always ready to go.
If you're looking to go beyond Google, there are dozens of combinations, and you can have multiple search engines selected. There's an extensive list of search portals buillt in, but you can add your own by simply providing a URL.
In the open Phlo window, you can start to type the name of a search engine and it will pop up for one-time access. You never have to use your mouse, and multiple sites can be chosen with shift + return or shift + click if you want to use your mouse. Out of the box, Phlo is configured to pop up with option + spacebar, but you can define any key or combination. Apple Spotlight uses Command + Spacebar. The ESC key closes Phlo.
After you've used Phlo for awhile, it becomes second nature. I found it to be a timesaver, because your searches begin with just a tap on the keyboard, and I find myself doing more searches because it is so easy to get them started. The only change I would make in this app is an ability to create groups of search engines for specific tasks, and have Phlo remember those groups.