It's not just an iPhone version, but should be pretty compatible with most mobile devices. The best part though, is this isn't just a way to read the articles like previous mobile versions have been. This is a full-featured mobile site, meaning complete archives of all archives, the comments, and the ability to comment.
Since CSS-Tricks is on WordPress, I always wanted to figure out a way to have a mobile site at a subdomain or subdirectory that would serve up the same content, but using a different WP theme. I never quite figured out how to do it, but it doesn't matter now because that is essentially what Mobify is doing.
Mobify can work on any site really, but I'm pleasantly surprised at how well it has integrated with WordPress. Not only does commenting work just fine, but they also have a plugin which handles re-directing all mobile visitors automatically with zero work on your part.
Doesn't Kill Your "Full" Site
Normally I frown upon "mobile versions" that serve up special content to mobile viewers with no way of viewing the regular full site. Mobify doesn't do that. It does redirect you, but if you want to head back to the main site just click the "full site" link at the bottom. That is the ideal method if you ask me.
Mobify is partnered with AdMob for delivering you mobile analytics. I think there are still some quirks to work out and honestly it's not working for me quite yet, but I imagine they'll get it worked out soon.
Do It Yourself
Mobify is a self-serve system. You build your own mobile version with their Design Dashboard, giving you full control and previews of what you are building in multiple devices.
Thanks again to Mobify for the help putting this together. If ya'll would like to see other sites that have used it, I Love Typography has one, A List Apart, I think Six Revisions is getting one soon, Veerle has one, the Dieline, all kinds of awesome sites.