¡México Decide! may be the most interesting one I've seen yet.There are a lot of websites where you can share information and discussion about the forthcoming US Presidential election - but
Arguing that the US has huge influence in Mexican elections and that Mexican immigrants, both legal and illegal (undocumented), are fundamental to maintaining the US economy - ¡México Decide! concludes that all immigrants, legal and illegal, ought to have some say in the US Presidential election.
The site provides a place for immigrants and others to share information and discussion on the candidates and their policies. It also includes profiles of Mexican immigrants who have lived and worked in the US for years but who are not yet documented citizens.
¡México Decide! is the creation of artist Ricardo Miranda Zúñiga, whose previous work includes the video game Vagamundo: A Migrant's Tale.
This project was profiled today on the excellent blog We Make Money Not Art, where you'll find several links to related resources, information and perspectives that could help keep you from making a fool of yourself saying something stupid in comments.
Immigration is one of the key issues in US politics today, both on a policy level and as a metaphor for our larger relationship with history and the world we live in. I'd love to see more read/write type web projects engaging with these issues.