Built in Python, ShortWiki lets you edit a wiki via SMS:
From the README:
Text “HelloWorld Hi! :)” to your number. This writes a wikipage called “HelloWorld”.
Now text just “HelloWorld”. You should receive “Hi :)” with a footer signature.
You can get a friend to text something like “HelloWorld lolcats!” to edit the page.
Now when you get “HelloWorld”, you’ll see “lolcats!” by your friend and when.
Make lots of pages! Serve up microcontent over SMS. :)