I was thinking about firing off some GNS3 labs as exercises for everyone to use.  My thought was that I could generate a few small networks with a requirements doc and have people do the leg work as practice or for a study aid.  You know, configure OSPF over this frame relay network or GLBP for load-balancing gateways.  I gave up on that dream (like I do a lot of them), and wound up clicking around on GNS3 Vault.  Rene Molenaar has already thought ahead and developed about 60 labs exercises that can be downloaded.