xpro.se

Cisco IPSec VPN:
http://mnshankar.wordpress.com/2010/05/17/ubuntu-10-04-and-vpn-at-uf-2/
http://www.nulldevice.de/2010/06/cisco-client-vpn-vpnc-ubuntu-linux-10-04/

Out of the box support for PPTP VPN in Ubuntu 10.04:
http://computergyan.wordpress.com/2010/04/21/out-of-the-box-support-for-pptp-vpn-in-ubuntu-10-04/

Here’s another university that uses the normal 10.04 network manager without vpnc to connect a PPTP VPN:
http://www1.umassd.edu/cits/wireless/vpn_linux.pdf

Read more about Ubuntu 10.04 and it’s pre-installed VPN:
https://wiki.ubuntu.com/VPN