Style Not Substance

The results of Challenge #17 "Rectangles" are:
( results )
Thank you, everyone! Thank you especially for the overwhelming vote. Wow.

I've also revealed the entries in the challenge entry post.

Now, discuss! How did you come up with the ideas? How did you create them?

Welcome to challenge #17, "Rectangles". For this challenge, each icon you make must use rectangles as part of their design.
This challenge is now CLOSED. Entries have been revealed.
( more and rules and dates )
In short:
Due 15th of February, post entries here, don't show them elsewhere.

If you know any good tutorials for this challenge, please post a link.

And please pimp this far and wide!