I came across Mac Explorer the other day, and it looks neat. But I wanted to solicit opinions on either it, or other good Finder extensions, add-ons, etc. that people really like (besides LaunchBar - already own it).
I second Quicksilver. It is definitely one of the coolest and most intuitive/genious programs I have installed on my mac. Give it a try, you won't be disappointed, and you won't uninstall it.