I’m not sure if any of the other math blogs have pointed this out yet (I haven’t been very good about writing OR reading blogs the last few months) but Google Wave is now up and running. Terry Tao discussed the potential use of wave for math collaborations back when it was first announced. While wave is only available by invitation at the moment, there are a number of mathematicians who are now using it and if you ask around you can probably find someone with an extra invite to send you.
While wave, like google docs, does not have built-in support for LaTeX, a number of people have written bots for wave that make it function like a WYSIWYG LaTeX editor. There are three that I know of: eqygadget, la-texy and watexy. If you add one of these bots to a wave, it will convert LaTeX math code inside the appropriate delimiters into an image of the symbols. My favorite is la-texy (add email@example.com to your wave), which processes anything inside double dollar signs. To turn the image back into code, you put double equal signs around it. At the moment there’s no easy way to convert the whole document into pure LaTeX code, but this function has been requested on the bot’s web page, and it seems reasonable that if they can convert one image back into code, they should be able to convert all of them. This would make wave a very powerful tool for coauthoring papers with distant collaborators, without having to worry about which e-mail attachment is the latest version of the paper.
Having experimented with wave for a few weeks now on a couple of collaborations and a workshop organizing committee, I think it has the potential to make a lot of things easier and more efficient if people become as familiar with wave as they are with e-mail. Right now it still has novelty status, so many people don’t check their wave inbox regularly and discussions die after a few days. (I have my wave inbox set as one of my web browser start pages, to make sure that I look at it.) But hopefully once there’s a critical mass of users and everyone has a reason to check their inbox as often as they check e-mail, this problem will go away.