Parang is a plug-in for Safari that lets you search from the location field using search keys. For example, you can assign "g; to google. Then, for instance, if you want to search google for "dogs and cats", you just type "g dogs and cats" into the location field. You can also specify what spaces should be replaced with. It might be "+", "%20", "_" or anything else. Search engines are very easy to add and manage yourself. Parang also lets you do an "I am lucky"-search, by holding alt/opt when you hit enter/return. It will install as a preference module in Safari. Install instructions are in the readme file.