It's on github (https://github.com/mashape/unirest-obj-c), so I expect someone will submit a podspec in the next 24 hours. One of the awesome things about CocoaPods is you can also write a podspec for a repo you don't control. So even if the creators refuse to add CocoaPods support, you can still use CocoaPods to import it to your project.

edit: went ahead and added a pull request for a .podspec. Only a little bit of extra work, since I was writing one to test it out locally anyway.

here: http://cocoapods.org/?q=unirest