How to search twitter

Hi everybody,
I need serious help to find on twitter only USA person.But i don't know how can i find USA person ASP in twitter?So,i need your help.Waiting for reply from twitter master..............:shakehand

Tried http://pipl.com/?

EDIT: I also use http://search.twitter.com/advanced/ (Dunno if that's more suited to what you're after)

Hope it helps a bit.

wow for real

If you know someone is on Twitter but don't know where to find them on Twitter you'll need to use Google as Twitter's search seems to give quite a bit of privacy to their users whereas Google is the search monster that will prove fruitful most of the time.
What you want to do here is to start out with a general search for the person's name followed by "Twitter" which may (depending on the popularity of the person's name) quickly return their Twitter profile location in the results.

jason2009 Twitter
This may return a lot of results and is where you'll need to narrow down the search using a couple of Google search functions.

jason2009 + "Location:Newyork" site:twitter.com
The search above is guaranteed to find all Twitter profiles that have the name "Jason 2009", the location "Newyork" and are on Twitter. Depending on the popularity of the name at a particular location will depend on the amount of results however this really is the only decent way to find specific people on Twitter. So whether you're searching for an old friend, relative, celebrity or just a specific person then this is what you'll need to do.

Twitter's built in people search isn't the greatest way to find people on Twitter, but it's probably where you should start.

TweepSearch lets you search by Twitter name or location

I would search "Twitter + username"

You might want to check out this interesting article :
http://windmillnetworking.com/2011/07/07/search-twitter-for-people-by-location/

dude just use simple search button..its quite simple