skippy is tweeting for health care and has a list of twitter addresses for key congresspeople.
Tim F. of Balloon Juice has a guide for calling your congresscritters.
Meanwhile, David Dayen (DDay) continues to update his whip count for the House of Representatives based on public statements.
If you live in a swing district, your voice is especially important. But as Tim F. has pointed out, even if your representative and senators are pledged to vote the way you want, it might be nice to give them a thank you call. The far right is deluging offices, and it's important that the full range of public opinion be represented, preferably accurately. I think the bill is flawed, but it's still a huge, important measure.