We have just released the new version of the Securing Networks with Cisco Routers and Switches (SNRS) remote lab exercises. They are an ideal companion to books or e-learning material if you're preparing for the CCSP exam. You can also use them as a great practice environment if you have to support security-related IOS features in your network, but simply don't have the extra equipment to test them out before deploying them.
As a side note, what really amazes me is the fact that Cisco has rolled out a mainstream certification course that supports pretty recent features (up to IOS release 12.4(6)T), including control-plane policing, management-plane protection, zone-based firewalls and Web VPN.
More information is available here.