Really? How would I enable this? I don't see anything in prefs for Safari 3.1.1.
There's the "logout" link on this page, I just start typing l-o-g..., and once it gets highlighted, I can hit return and it'll click the link for me. Or if I need to go to the next word, I can still hit command+G. I don't have to invoke Find either, I can just start typing.
I guess the equivalent in Safari would be to cmd+f, type your word or phrase, press escape, then press enter. A couple extra steps but it does the trick.
This is really the main reason firefox is my default browser.