Could be done fairly easily though, I really like the JanRain implementation of OpenID login for Wordpress, nice user friendly popu up box that includes site login, and a bunch of host selected other services to click.

DW could possibly even leave the choice of specific services for the login splash to the journaller or comm maintainer; I'd want the LJ, Twitter, Blogger, FB and WP logos displaying prominently, but others might want journalfen or IJ or similar. As long as the OpenID logo is there as well, we're good.