Multiple users post to a single blog.

Issue Summary

This is probably a little harder to implement than the other things I suggested but here is my idea...

When a user creates a blog they should be able to select other users that are also allowed to post to that same blog.

Here's how this would become useful in my situation:
I run a site where people submit and make their own computer games. I use the everyblog module for people to have a development blog about the progress of the latest game they are making. But often multiple users work together on the same game, and the problem is that only the person who created the blog can post to the blog. So I suggest that when a user creates a blog, they can select other users that can also post to that blog. This way all the people working on the game can post about it.