First, I gotta 'fess up to calling the VP selection, and the date of the announcement, entirely wrong. But it's nice to see that Obama can still surprise me, even if it wasn't a surprise to anyone else.
At any rate, I haven't gotten my text message yet! I got the confirmation one when I first signed up, I texted back my ZIP code after they asked, and eagerly awaited my VP Text for the last week. And now I find out everyone else has gotten it, but I haven't. What up?
But that got me thinking... what's the point of this whole text message thing anyways? Then it hit me: Nov. 4th!
They've got my cell-phone number and my zip code. Imagine on election day, they send out millions of text messages reminding people to vote, and more importantly, reminding people to remind their friends to vote (since anyone who signed up to get a text message regarding Obama's VP announcement is presumably not going to forget about election day).
So that's cool, it's distributed GOTV on a massive scale. It's brilliant, really. But the zip code thing is almost fiendishly clever. 
Imagine it's election day, and Obama's field office in Ohio realizes that a couple of districts aren't going as well for them as they were projecting because it's raining and a major freeway is jammed up with a big accident. They can send out a message to thousands of supporters in those districts saying: "We really need your help in Ohio. Please call everyone you know and remind them how important it is that they vote today. And if you're worried about traffic, we've posted alternative routes at www.barackobama.com/ohio."
Obama can send out thousands of these in the time it takes to phone a single voter with that same message. And a traditional phone call is wasted if the recipient isn't at home. That text message will reach nearly all of their intended recipients even if they're at the gym, at the supermarket or at work, and it'll reach the growing class of people that don't even have a traditional land-line anymore.
That's why they encouraged people to get their friends to sign up for the text messages. That's why they asked for your zip code. And that's why they didn't announce his VP pick until the last possible moment: The longer they waited, the more people signed up. The last two weeks of frenzied media speculation on his VP pick have surely driven millions more people to get in on the text message scheme.
It's easy to imagine that if texting were as widespread in 2000 as it is today, and Gore's campaign had the savvy and foresight to use it, he could have more than made up those few hundred critical votes in Florida. 
I noticed during the primaries that Obama's team clearly understood electoral tactics. This let them get a delegate win in Texas despite losing the popular vote there by a pretty substantial margin. I think we'll see that the primaries were just a preview. They've got a ground-game operation going that's not only better than McCain's, it's revolutionary.
In other words, this is a very bad year for the GOP to be fielding a candidate who doesn't know how to send an email. The difference between Obama's ground game and McCain's is the difference between rocket ships and golf carts.