BitlBee has support for identi.ca, an open source social networking and micro-blogging service based on the OpenMicroBlogging specification. It uses the same protocol as twitter, but defaults to a base_url pointing at identi.ca, and with OAuth disabled.
To use your identi.ca account in BitlBee:
From version 3.0.5 and higher, OAuth for identi.ca will also be supported so connecting to identi.ca will be just like connecting to Twitter.