you could also hook up the sensor to an iobridge.
Read the articles in this month's MAKE about Tweet-a-Watt and the Garduino. You should be able to figure out how to adapt the XBee interface on the former and place it on the latter. Then you set up your cell phone to pick up the RSS feed from your Twitter account, and you're done. Once you're finished, make sure you write up your own Instructable and post it.
LadyAda posted a longer version of her MAKE article about the Tweet-a-Watt (with complete info) on Instructables here.
Yes, she did, and that's what I linked to ;-> The Garduino link above is also to the corresponding I'ble, not to MAKE's online article.
That's awesome. I want one too!