Amongst these other goodies in this SmashingMag post, I really like this clean, simple a nice navigation menu, designed by Nick La.

"A unique UI control that allows users to select from a complex hierarchical tree of options. Intuitive and it allows for both quick mouse and keyboard entry. Resizes and positions to stay in the viewport. Options do not show up off screen where users would need to scroll to select them. Quick keyboard entry. Many users prefer keyboard entry for speed of data entry, so efficient keyboard entry is a must. Able to handle very large complex (deep) data trees, but works equally as well with very small sets of data. Easy."