I pitched this idea over a month ago to the rest of the developers and I was shot down. Here's what I wrote to them...
"
TypeKey is a user authentication technology I
first saw being used in the latest version of
Geeklog (one of my favorite CMSs) that was released late last year. The system works by creating a central user database for multiple sites to log in with. Much like how Gravatar lets you take your icon from one site to another, TypeKey lets you log in to several sites using the same credentials. If integrated with Pligg users would be able to log in to any Pligg site with the same credentials. So if you are signed up for an account with Pligg.com you can log into Shakk.us with the same username and password. Currently TypeKey is being used for Blogger and LiveJournal accounts, which means that if a user has a Blogger account they could log into a TypeKey enabled Pligg site with their Blogger username and password.
The big reason I would like to have this feature built into Pligg is so that we can have a centralized user database. That way we could share users between all Pligg sites and make it more convenient for users to log in to sites without having to go through the registration process over and over again."
If you really want this feature I would suggest gathering some $$$ to influence the rest of the developers. I think it would be a great idea, but I only have so much say as to what goes ito Pligg when it comes to major features like this. It would also cause a problem with previous Pligg installs needing to convert over into the new login system.