I've been trying to make a list of websites, services, and the like that make use of SMS features. Some of them are obvious like the microblogging services (twitter+world) and the FOAF social network sites (facebook, myspace, etc).
What are some interesting, useful, or creative uses of SMS integration that you guys have seen out in the wild?
As for myself...
I've been using QR codes to bookmark interesting websites from my desktop (mobile barcoder plugin for firefox) to my mobile device. My mobile device than publishes that link to a special twitter feed of 'what sites i am reading now' via SMS.