A picture may be worth a thousand words, but in this case it just needs to be worth 140 characters. Everyone likes to look at pictures, and Twitter users are no different. Take the image of the US Airways flight 1549 that famously crashed into the Hudson River in January 2009. That image was posted and reposted on Twitter more than 350,000 times. If you were one of the early posters, then you had a good chance of picking up a lot of followers. If you're on the go and you have an iPhone, use applications like Tweetie and Twitterific to upload pictures wherever you are.