There's no doubting that Twitter can net plenty of traffic if you hit a popular topic at the right time. Twopular helps you identify popular topics.
On the home page, you can see the most popular topics on Twitter categorized by the last two hours, 8 hours, day, week or month. There are small arrows that will also tell you how the term is trending and a number indicates exactly how popular the term is across Twitter. Click on any of the blue-shaded terms and see the ongoing discussion on Twitter about that term, as well as a list of popular topics on the right of the resulting page from Twitter.
An interesting feature is the search function at the top of the page. Enter a term and click on the result in the list, and you will see the trends over the last several weeks, as well as the top trendsetters and retweeted people for that term. Not a bad way to target a user to help you spread your tweet around.
This tool could be a great way to target topics to tweet, and increase the likelihood of getting attention, retweets, followers and traffic.