PayPal and Facebook have joined the OpenID Foundation, and will now work with the rest of the community. This is great news for new developers and social networking entrepreneurs, as Facebook brings their membership heft and User Interface chops, while PayPal brings their security experience and the potential of a payment platform tied into the OpenID.

If you haven’t brought OpenID into your application yet, there’s now no reason to wait. Your users will be able to log into your site with their OpenID account, and bring their identity and friends with them. This will increase new signups, improve the richness of your application, and reduce the friction of “network overload.”