Google Buzz does not directly support SMS posting, but there is a quite tricky workaround that can be useful, if you are not constantly in WiFi or 3G coverage area.
The only purpose of this "blog" is to be a part of the SMS to Buzz gateway structure. Thus no public access, no comments, feel free to leave them on my Buzz or Twitter. ;)
Since I cannot use Google's Blogger.com's SMS feature (I have Malaysian cell number, so even GV is still not a solution, yet), and I really dislike Wordpress so had no interest in finding out will it support SMS or not (seems like it wouldn't anyway) I had chosen Ping.fm as an intermediate between the mobile carrier and Blogspot.
After Blogspot receives the SMS request, the scenario is almost identical to Tyler's:
This blog serves as the SMS to Buzz gateway (after Ping.fm)
Route the blog’s RSS or Atom feed through FeedBurner
Add an XFN “me” link from the blog to the Google Profile
Add the blog as a profile page to the Google Profile
Have Google re-crawl the blog
Add the blog to the Buzz stream
As a result, no matter if I am in WiFi or 3G coverage area, I always have access to FB (via Celcom SMS) and Google Buzz (and to whatever services I link to it: twitter, gtalk status, etc.) instantly, over good old SMS. The only downside is that I need to send an SMS to a UK number, but it costs very little nowadays.