The syntax to make a post is as follows:

twidge update "whatever you want to post goes here"

And before you do your first update, just type twidge setup, which will then ask for your usename and password.

If you want to update identi.ca rather than twitter, then add the following line at the end of .twidgerc:

urlbase: http://identi.ca/api

And that’s all there is to it.