NetworkManager - Linux Networking made Easy

NetworkManager is the most important recent improvement for truly portable laptop Linux. Period, full stop, whatever. I am rarely wired. I use a half-dozen wireless networks in an average week, more if I'm traveling out of town. Network Manager makes managing wifi as easy as it is in OS X. The UI is stolen from there, really. And as a bonus, there was a VPN plugin that ended my file-based configuration struggle with the pptp and pptpconfig packages.

Network. Manager. Just. Works.

(Caveat, network manager was not trivial to set up. Once I downloaded the package, I had to "disable" the existing management of my network devices. It was not a beginner task.)