Yahoo! launched today a microblogging system in portuguese called Meme. I don't really know why is only in portuguese, but I tested it think it has a nice interface, it doesn't have the annoying 140 characters limit and it allows you to post videos, mp3 and pictures too.
I couldn't find info on an API, so I'm not sure if it will be easy to integrate wih other tools, including Twitter itself, Facebook and all that Mash Up Godness.
Web standards oriented people won't like to know that although the interface is very slick the site is not very useful without javascript.
In any case, I think it's worth checking out and if you need an invite I have 10 to spare, just ask me here, on twitter or on comments!