Search Long Tail Keyword by using Google Suggest
Google has post about they will roll out Google Suggest as a default feature for the Google.com homepage.
Google Suggest will be “graduating” from Labs and available by default on the Google.com homepage. Over the next week, we’ll be rolling this out so that more and more of you will start seeing a list of query suggestions when you start typing into the search box.
This feature will reduce your time to get the best results by Google Suggestion with the best keywords and phrases. Google Suggest features include : Help formulate queries, Reduce spelling errors, and Saves keystrokes.
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.
This is an example about finding a long tail keyword with google suggest :

I try to find Busby SEO Challenge in that search form. But before I finish in typing the keyphrase as you can see in my screenshot above, Google suggesting a list of recent search (if I’m not mistaken). I think this a part of Google Suggest Save Keystroke features.
I see Busby SEO Contest, Busby SEO, Busby SEO Challenges, and Busby SEO Challenge devianart on their suggestions. I think Google will only show relatively popular keywords based on what you type and recent search. Because Google give a list of suggestion, I think we can target our next post or blog or site based on what google suggest. And I think people who use Google when they seeing this suggestion they will choose that suggestion.
seroundtable.com has wrote about Google Suggest to Change the Ways of Search Engine Optimization, or join discussions on Sphinn : 9 Ideas How Google Suggest Could Change Search Marketing, and Google Suggest Will Greatly Change Keyword Referrers.
I tried to compare this new feature of Google with Yahoo Search Assist. Again, I type Busby SEO, and they give me suggestions just like what you see in the screenshoot below.

