Well interestingly enough - I don't know how many people have seen this or if this has been posted at WebProWorld.com but google's placing a search bar in the search results - so far from what I've checked out - only for domains that have sitelinks.
Check this result for a search on craigslist:
craigslist - Google Search
Or this for a search on OSCommerce:
oscommerce - Google Search=
Neat!
Am I new!?