The new version of Movable Type has built-in support for OpenID commenting, which is great. I like the approach of presenting people with familiar icons to communicate the idea that the already have OpenIDs, and being able to hide all but the username and fill in the rest, they don’t even need to know that they’re using an OpenID. I’d like to see TypePad and Vox (and Blogger) add in OpenID support like this, too.