There are countless ways to update Twitter these days, so I’ve tried to round up as many of the ways to update as possible. I’m sure I’ll miss a few so make sure to keep me informed by letting me know in the comments. Also, make sure follow me, LostInTech, on Twitter.
Twhirl – Twhirl is probably the most popular desktop client. It also supports TwitPic, TweetScan, FriendFeed and cross posting to Pownce and Jaiku.
Spaz – Desktop client for Mac, Windows and Linux
Tweetr – Allows you to send files to other Tweeters. It also has a built in webcam feature.
Alert Thingy – Keeps you updated on FriendFeed and Twitter. Allows you to easy upload pictures to Flickr.
TweetDeck – Better organize your Twitter friends with a great built in group feature.
Twitteroo – Displays updates without pictures (for better or worse).
Witty – Open source client for Vista and XP
bTT – Non-Adobe AIR based desktop client.
Twitterlicious – Minimalist desktop client.
Snitter – Customizable desktop client for Mac and Windows. Feedalizr – Post to FriendFeed, Twitter, Jaiku and Flickr with this desktop client.
Posty – Has support for several microblogging services
twitbin – Creates a sidebar for Firefox to keep you updated.
TwitterBar – Post updates from your address bar.
TwitterFox – Puts an icon on your bottom bar that gives you notifications and allows you to update.
Firefox Search Plugin – Post updates from your search bar.
TwittyTunes – Show people what you are listening to.
Twitterfeed – Update Twitter with new posts from your blog.
Brightkite – Brightkite updates can be synced to update Twitter as well. Twitio.us – Twitter + Del.icio.us
Twitthat – Bookmarklet that lets you Twit about the web pages you are viewing.
HelloTxt – Update all your services in one place
Ping.fm – Updates multiple mircoblogging services
PingTwitter – Send updates when your blog updates
Socialthing! – Lifestream plus ability to update.
Sendible – Organize your online life.
Though some of these services are no longer live, you can try out the ones those are still up and running. If you would like to recommend any personal favourite to the list please add them in your valuable comments.