Virtual Private Network Configuration for the Cisco 1700 Routers (sone info about setting it up on 12.0.1T, but no examples.
some actual useful info on the 1700
Configuring IPSec Router-to-Router, Pre-shared, NAT Overload Between Private Networks (ie: Router-to-router VPN tunnel)
IOS IPSec NAT Transparency with VPN Client Configuration Example - Ciscowiki