As you can tell by just looking at its name, this is an application that brings together text messages and Google Buzz. In practice, what you can do through it is to post the updates that you publish on Buzz through text messages.
I think this service could be useful in (very) specific cases only, such as transmitting information like a change of plans when you are to meet with someone and either the time or the place has to be modified and you want to ensure that such a fact is getting through to its intended recipient(s) in more ways than one.
Other than that, I think that most people could live without such a system, for the mere reason that Buzz did not catch up to the degree that other services like Twitter have done.
As a service, Buzz Via SMS is provided absolutely for free. That is, you are not charged for using the service itself. Text messaging costs will depend on your existing cell plan, so keep that in mind before you start texting out.
BuzzViaSMS.Appspot.com In Their Own Words
“The simplest (and only) way to post to your Google Buzz account through good old text messaging.”
Why BuzzViaSMS.Appspot.com It Might Be A Killer
It combines two services that are not often paired, and that gives it a sort of exclusivity.
Some Questions About BuzzViaSMS.Appspot.com
Will people really use it? 
