A friend of mine has just released his latest tool for Zbrush, Zswitcher. The gist of if it is that it clones Maya's navigation UI into Zbrush. You can download and try it out right now.
There's obviously much more to it that just that, but I'll point you to their info as they know it better than I. They have an online help page plus a discussion forum so you can ask questions and give him some feed back. They have more than just this as well, stop by their front page for potentially more bits of fun.