How many times have you looked at the Twitter trending topics list and said, “Huh?” That’s assuming, of course, that you’re on the Twitter web site and that trending topics are visible in your sidebar!

No need to scratch your head in wonder any longer, however. Bookmark WhatTheTrend? to see the top trending topics on Twitter as well as a short explanation of why the topic is trending.

Yes, this is a human-powered tool, with all the shortcomings that implies. It is a “personal web experiment by Matt Mayer, a Shanghai-based British web developer for RIA agency ReignDesign.”

The WhatTheTrend? page does not auto-refresh in Firefox 3.5.2 (Mac), but a quick command+r will solve that nit.

And the web site is not always going to have an explanation, as the introductory screenshot reveals. Also, the site may not present the latest trends in the order that they appear on TwitterSearch.

However, click through any trending topic and you’ll find representative tweets, news headlines and images. That’s adding a bit of value! Those links take you, in turn, to the appropriate Twitter search, Google News search, and Flickr search.