On hacker news (i.e the better alternative interface http://hckrnews.com), I stumbled over two nice helper apps for Mac OS X:
FinderPath (free) shows the full path in the title bar of a Finder window upon double-clicking it. Like that, the full path can be selected and copied to the clipboard or one can simply edit the path and hereby easily navigate through the filesystem trees. It’s quite a time saver!
HyperDock (9.95 USD) displays thumbnail screenshots of all windows of the running apps in the Dock when hovering over them, making it easier and quicker to switch to other windows or to close them (the latter being a feature still missing in Mission Control). It also supports several other cool features, like Window Snapping.