VPN

VPN stands for Virtual Private Network, of course. Not to be confused with a VPDN, and often implemented using IPSec, PPTP or L2TP.

Resources:

• PPP over SSH
• OpenVPN - an interesting twist.
• vpnc - Cisco-compatible, no certificate support (yet!)

PDA solutions:

• Pocket PC 2002 and 2003 include a PPTP client
• Mergic make a Palm client (but no Palm OS 5 version is available yet)
• TrustDigital