Google is launching, “Google Suggest“. It appears to work somewhat similar to Yahoo’s search suggestions. According to Google here are the improvements Google Suggest brings.
“Help formulate queries: Instead of just typing [hotels in washington] - did you want [hotels in washington dc] or [hotels in washington state]? Don’t remember that song title or person’s name? Let Google help you search (and yes, I ended up choosing “From This Moment” as our wedding song).
Reduce spelling errors: Since suggestions are spell-corrected using the same “Did you mean?” feature that offers alternative spellings for your query after you search, misspellings and typos can be corrected ahead of time. Instead of wasting your time with a misspelled query like [new yrok times] or [tomorow never dies], search the first time with the correctly-spelled query.
Saves keystrokes: Who wants to spend their time typing [san francisco chronicle] when you can just type in “san f…” and choose the suggestion right away?”