If you are willing to engage with Google (corporate motto: don't be evil!), there's Google Buzz. It's sort of somewhere in between Twitter (in that it's real-time, automatically distributed to follower's Buzz pages, etc) and LJ (in that there is no 140-character limit, you can post pictures, etc).

The 140char limit in Twitter is a hold-over from when Twitter was mainly SMS-based, which used a normally-unused channel capable of sending 140characters.