There are many sites out there offering Twitter post extenders and so on. They offer up the usual kind of thing, you login with twitter, you post then it links to the extended post using what ever URL the site they own to your feed. This is all well and good and sites like Tweetlonger.co.uk offer a fine service.
Tweetbase is a personal project developed by 1 coder (That's me....) with the sole aim to build a downloadable Twitter post extender, one that was more personal and aimed at the single user. So any tweet that come in at a character count belolw Twitters maximum character count will be sent to Twitter as a normal post with now links as they would not be required. Anything over their stated maximum character count would generate a bit.ly link to the post and post an abreviated version to Twitter linking them to the authors twitterbase post on their site.
Please see this page for install instructions.