Dave Kearns asks by e-mail:

Isn't it tremendously useful if all LID URLs hosted by the same service provider have the same format (i.e., http://yourdomain.com/users/jim/cgibin/lid.cgi)?

We were thinking about that. We thought that

http://yourdomain.com/~jim/

would actually be the most normal one because Apache is pretty much preconfigured that way and many ISPs map their users that way.

Alternatively, we were thinking that if

http://yourdomain.com/my/blog

is the URL of your blog (and thus known already to many users), then

http://yourdomain.com/my/blog/lid.cgi

or something like that could be your LID URL.

However, we rejected that idea because our goal was really to have only one URL for the person (well, the persona). Which means that using my blog URL as my LID URL (as I do) is a fundamentally simpler setup, and it provides the abstraction that we want to provide: there is one URL for a person, and depending on which arguments you provide (some, none, e.g. xpath=...) it returns different information.