I searched high and low for something like this, and while there are a few others that have some of the same functionality, this one is my fave. I love the granularity with which I can set access. It came in handy recently when I needed to give a developer admin access to my site to troubleshoot an issue, but I wanted to play it safe. I was able to block the developer from adding, removing, or editing other users (which just seems logical), yet they still had full access to everything they needed to fix my code issues. I've also been able to give my blogging partner access to lots of admin things she needs to see while keeping her out of editing code, updating plugins, and other things she simply doesn't know anything about. Using this plugin gives her all the access she needs, and keeps all the other mess out of her dashboard menu, so it's not so overwhelming, and scary mistakes are impossible.