TweetReach allows you to enter a URL, Twitter name, phrase or hashtag, and discover how many people it has reached and who is talking about it. Give it a try at www.tweetreach.com and discover your reach!
Just about everyone is on Twitter nowadays, so find the people that you look up to and who you deem influential, and follow them. You might even be able to use social media to connect with them in person.
Before heading to a conference or meeting, find the attendees on Twitter and connect with them. Chatting through social media first will make it much easier to network and connect in person.