Taking inspiration from omz's Evernote SDK installer, I've went ahead and scratch my own to deploy Boto in Pythonista. The gist can be found here: https://gist.github.com/najibninaba/5062153
Run this script in your root folder and boto along with its dependencies will be installed in the boto-module folder. To use it, be sure to append the boto-module folder in sys.path and you should be good to go!
I'm able to create a EC2 connection and query my instances and key pairs. Do try it if you have an AWS account and let me know how it goes!