Mac OS X application that's sleek and minimal and lets you check on friends' posts ("tweets") and post your own, without cluttering your desktop.
Basically, Twitterrific but for Windows, offering the same blend of easy reading/updating for PC users.
Two services from the same people. Twittervision plots recent tweets on a big Google Map of the world, while Twittersearch lets you enter a search phrase and see all recent tweets mentioning it. Yes, I know this makes this a Top 11...
A Twitter client for Second Life, so you can read friends' tweets and post your own from within Linden Labs' virtual world. Zeitgeist-tastic!
5. Tiny Twitter
Small but perfectly-formed Java application for mobile phones, which lets you post tweets and check on your friends. It's bare-bones, but right now that's what keen Twitterers need.
Turns your blog's RSS feed into tweets at pre-defined intervals. Could tempt commercial blogs as well as personal bloggers.
7. Post To Twitter
Another simple one – it's a Firefox plugin that lets you post tweets from the dropdown search box at the top of the browser.
8. WHERE GPS Twitter widget
Part of the WHERE GPS widgets service for phones in the US, if you've got a GPS-enabled handset, this adds your location to your tweets posted on the go.
This online service tracks the links that people are posting on Twitter, sorting them by popularity and giving you hourly or weekly views.
Another OS X application, but this lets you - with one click - post what you're listening to in iTunes, what URL you're looking at in Firefox or Safari, and a bunch of other variables. ®