The @trendingtopics Twitter bot tweets the topics that people are talking about most on Twitter. There’s also an RSS feed if you’re interested. It’s a very low tech solution and it’s not guaranteed to work but I find it quite useful.
How it works: I used Dapper to ’scrape’ search.twitter.com and output an RSS feed. I then tried to feed this into TwitterFeed but that didn’t work because TwitterFeed requires each RSS item to have a date or a GUID. So, in an effort to stay with the web mash-up spirit I tried to use Yahoo! Pipes to copy the <link> of each RSS item into the <guid>. I nearly got it working but in the end I gave up and just used a custom PHP script on my website to do it.
If there’s demand I may improve the script to filter out very similar words (i.e. “Olympic” vs “Olympics”) and keep track of historical trends but in the meantime, try it out and let me know how you get on.