Text messaging with Ruby on Rails

I want to create a text messaging system with my RoR web site. Anybody
know of any good plug-ins or gems?

I found this which is about 6 cents per text message:
http://www.lukeredpath.co.uk/2007/8/29/sending-sms-messages-from-your-rails-application

Anything else out there that is reliable?

Thanks
Chirag

Hi there, I'm the author of the Ruby Clickatell gem. There are plenty
of SMS gateways out there; I chose Clickatell because they are one of
the bigger gateways who provide services for plenty of big names (BBC,
CNN etc.). There rates aren't too bad. You might be able to find one
thats a bit cheaper I guess, but not that much. Remember that if you
buy credits in bulk you'll get a better rate.

Cheers
Luke

Matthew,
Thanks everyone including you for the great feedback! What do you mean
by "charged" and "uncharged"? And also are these gateways (MXTelecom
and Quinsy) good only in Europe? We're based in the States.
Chirag

You don't need any API or framework to send sms messages. All you have
to do is send an email to the person's phone and the carrier's gateway
will convert it to an SMS message. It works almost instantly. Eg.

#{10_digit_number_@#{carrier_gateway}

Here's a cingular/att example:

5555555555@txt.att.net

You just have to serach google for the list gateways for the other
carriers...