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: 
Where you can really make a difference with GUI design is if you are addressing a difficult to understand concept in a GUI.

When you are doing that, creativity is critical. When dealing with complex hardware configurations (something I had to do a lot, but probably doesn't apply to you), I've had good luck going to tech manuals and tech support people and trying to completely understand the problem. Then I took the methods they used to show me (diagrams from the manuals, whiteboard drawings, etc) and tried to code them into a GUI.

Had a couple massive successes with this.

Iteration is also critical. Prototype something quickly then beg everyone you see to try it. Ask them to solve a problem, then watch where they go first and watch what they have problems with.

Address every problem and stumbling block.

Don't be afraid to throw it all away and start over, it was only prototype code.

Separate your GUI from your implementation so that you can swap out the GUI if you find a better approach.
To make things usable, you need to make sure that you follow existing conventions for your target platform and application type.

For example, if you're developing a Windows App you'd better make sure that control-c copies, control-v pastes, control-s saves, etc. The File menu better be the leftmost item in the menu bar, and the Help menu better by the rightmost item. 

If you don't follow existing conventions, users are going to get annoyed with your application very quickly.