What other causes you would like to promote on Twitter?

You like the idea of promoting causes on Twitter by adding a color layer or a ribbon to a profile picture on Twitter?
I'm already working on a general version to promote other causes. Would love to hear what causes you would like to promote.

Examples of already working campaigns:
1. Green overlay/ribbon campaign to help the Iranian protesters - http://helpiranelection.com/
2. Yellow wristband campaign for LiveStrong foundation - http://livestrongaction.org/avatar

If you have other related ideas, please feel free to share.

Thanks, Arik.