Twilio's company blog, with tutorials on its voice and SMS APIs, product announcements, and customer stories.
HN commenters link it for how-to posts such as porting numbers and pricing explanations, and for customer showcases like Precision Polling. Twilio staff also point to it themselves.
We just launched a new gallery full of applications built with Twilio: http://www.twilio.com/gallery We also write about how people are using it one or more times a week on the blog: http://blog.twilio.com. We go to great lengths to promote our customers. We spend as much, if not more, effort on promoting our customer's projects and businesses as we do promoting ourselves.
I blogged awhile back about porting your mobile, land line, or Google Voice number into Twilio for free and hang onto it for just $1/month. You can also make it so your landline numbers can send/receive SMS once they're ported
http://blog.twilio.com/2010/08/how-to-port-your-212-landline-to-twilio-forward-to-your-mobile-phone.html
I tried to explain the various use cases and call legs in our blog post:
http://blog.twilio.com/2010/09/announcing-new-pricing-for-the-twilio-voice-api.html
let me know if this helps, if not I'll work on a better explanation
I literally laughed out loud when I saw this... great project. I'd start checking the Twilio blog (http://blog.twilio.com/) for contests and implement their API to do SMS and Call notifications, you might win something.
You may also want to check out http://PrecisionPolling.com. See our post on Twilio's blog today:
http://blog.twilio.com/2010/01/precision-polling-a-business-built-on-twilio.html