Question: I am working on a photo site and one of more active users asked about pushing content to cell phones. The site is built on django, and I was wondering if anyone knows a **good way of allowing users to download and store content (images) on their cell phones**?

As a side question... is it possible to accept payment for the content via the cell phone or would that have to take place on the site?

Answer: 
Google for HIG. Human Interface Guidelines typically include lots of research into best-practice in user interfaces, and explain in great detail how to design each aspect of a program. Also, have a google for "user-interface hall of shame" or something like that.
You can check case studys on websites of GUI companys. I fund few at [www.puzzlehead.com](http://www.puzzlehead.com)

Check there and also other sites.