If you love watching trends on twitter then twitterfall is for you. It takes into account the top ten trends or so and automatically updates with the latest tweets from the whole of twitter. It’s great becaues you can see the trends in real time without following six thousand people. A mere 340 should be enough 😉
On a more serious note it’s a very useful tool. You wake up in the morning and see what are the top twitter stories of the day within a very short amount of time. It’s global of course, so depending on the timezones you may see a different emphasis.
There is a local view too. If you choose keywords, for example Tuttle you can seleect the geographic region, London for example, and you will see all tweets from that geographic location.