This week tons of people were asking me “what’s the ‘Twitter’ of this year’s SXSW conference. See, two years ago at SXSW Twitter exploded onto the scene.

Looking back at this year’s conference (pretty tough cause I partied a little too hard with my new friends at Rackspace) it’s clear that this year is going to be remembered for when location exploded onto the scene.

First, everyone’s iPhones didn’t work very well for the first two days of the conference. Turned out that AT&T’s network was overloaded. I met the guy who fixed much of that problem on Sunday (they doubled the network capacity and turned on some new wireless bandwidth). That reminded me of the “Twitter SXSW” when Twitter itself was slow and went down a few times during the show.

But, that’s not the reason why this will be remembered as the “SMS & location explosion SXSW.”

First, it’ll be all the talk about a new app that got its first hype here at SXSW: Foursquare. Techcrunch wrote that up today. What is it? It’s a social app that you report via SMS where you are and it uses that info to build a little game with your friends. Lots of people were talking about it.

When I visited Governor Rick Perry along with a couple of other bloggers Chris Brogan was watching me use Ourdoings to email photos in from my iPhone, which posts them to my friendfeed stream along with a map of where that photo was shot, and he said “why aren’t you using Pixelpipe?” That’s an iPhone app that lets you upload groups of photos when you find available bandwidth. He said it was very valuable to him at SXSW when the iPhone often had very little or no available bandwidth (inside the capital building while we were visiting the governor we had the same problem).

Another app that got some attention at SXSW was CONTXTS, which are mobile SMS business cards. Daniel Graf showed me this. He asked for my phone number, SMS’d that to a number that CONTXTS uses and instantly a note came to my phone with his contact info. Very cool and useful for networking at conferences.

Here, you can try it with my phone. It asked me to “TELL YOUR FRIENDS TO TXT SCOBLEIZER TO 50500.” Now you’ll see how it works and you’ll get my contact information sent back to you.

So, how about you? Did you see any cool location-based services used at SXSW for the first time? There were a ton, like Google Latitude, or Radar, from Tiny Pictures.

Why don’t we list the coolest ones here, or on my friendfeed link, which I’ll post shortly?