Unfortunately, the Cisco AnyConnect client for Mac conflicts with Pow. And by "conflicts", I mean it causes a grey-screen-of-death kernel panic anytime you connect to the VPN and Pow is installed.
As an alternative, there is OpenConnect, a command-line client for Cisco's AnyConnect SSL VPN.
Here's how to get it set up on Mac OS X:
OpenConnect can be installed via homebrew:
brew update brew install openconnect