Searching tweets for keywords and topics helps you find people who are talking about topics of interest to you. The following Twitter tools will help you find people based on keywords in their tweets:

Twitter search-Searches all tweets for your particular topic and returns tweets matching your search in chronological order. Twitter search offers an Advanced Search option that lets you filter your results.

TweetTabs--Works just like Twitterfall, but also lets you create tabs to monitor a number of keywords. Search Twitter and follow the hot and emerging Twitter trends and tags in realtime.

CrowdEye-A search engine that shows you not only tweets based on your keyword search but also a time graph for when most of the tweets showed up.

Just Tweet It-A directory-based search that lets you register yourself under a directory almost as if it were the Yellow Pages of Twitter

Twitterfall-Searches for keywords and hashtags, and then automatically updates the results page, like a cascading waterfall.

Social Mention is a social media search engine that searches user-generated content such as blogs, comments, bookmarks, events, news, videos etc.

TweetDeck(a desktop application), TweetDeck’s search function lets you save searches for keywords and topics. -A robust search engine than most of the others in this list. You can search for bios, locations, and names.

Nearby Tweets-Enables you to search for people in your area and filter the results by keywords.Search, find, and watch local Twitter tweets from local users and businesses.

TwellowHood -From the makers of Twellow, a Yellow Pages–type directory that enables you to drill down to your city or town and see how many twitterers are there. Use a map above to locate Twitter people in your neighborhood who you can connect with.