For a site whose interface consists of a text field and two buttons, Google certainly spends a lot of time figuring out how to make the interface easier. Check out Google Suggest
What is Google Suggest?
As you type into the search box, Google Suggest guesses what you’re typing and offers suggestions in real time. This is similar to Google’s “Did you mean?” feature that offers alternative spellings for your query after you search, except that it works in real time. For example, if you type “bass,” Google Suggest might offer a list of refinements that include “bass fishing” or “bass guitar.” Similarly, if you type in only part of a word, like “progr,” Google Suggest might offer you refinements like “programming,” “programming languages,” “progesterone,” or “progressive.” You can choose one by scrolling up or down the list with the arrow keys or mouse.
Pretty neat. Typing ‘gadgeto’ brought Gadgetopia right to the top of the suggestions.