Ask HN: Use of OpenID provider logos

My site supports both a username/password login and OpenID through RPX (similar to ClickPass). RPX is a much better fit to my needs than ClickPass, but I wish I was able to use something similar to ClickPass's widget where the logos are displayed very compactly before you ever click on it (see HN's login page if you don't know what I'm talking about). RPX's widget require you to have your own link that then launches their code.

What I'm looking for is a very compact, but understandable way to express to my users (who are not necessarily tech-savvy) what the link might be for. Displaying all the logos of the providers I support would be perfect, IMO, but as I've looked into it that seems hard to get official permission for. So any thoughts on what else I could place in a link, or how one should go about getting permission to use the images? (For testing purposes, my link just says 'Sign In' right now, but as it's next to the username/password control, that is going to be confusing)