Thanks, rodavelino. You see, other twitter clients also support identi.ca, like mauku and witter. It's an useful feature, because identi.ca (I think the name of its engine is "laconi.ca") uses a FOSS framework for building a twitter-like service and that alone attracts many FOSS fans. A few of them use only identi.ca.

I don't mind that as much as them - I have an account on twitter - but I really like to follow them.

Thanks for your response!