XP Pro & Vista ICS workaround

I'm not sure if this means anything to anybody but I was playing around and thought it was better than going through ICS workarounds.

I have two laptops, both with CAT5 and wireless connection capability. One has XP Pro, the other Vista Enterprise. On the XP I recieve DHCP from my BT wireless router, which is fine. I wanted, through experimental purposes, to share my connection with my other laptop without wireless means.

So, using a crossover cable, one end into the xp and the other into vista CAT5 socket, (i actually had both set up with wireless disabled on ip ranges that allowed them to ping each other so that works, hence why this does), and on the xp i bridged the lan and the wlan together.

I then set the lan on xp to recieve dhcp and likewise for the vista lan

I had an APIPA problem on vista (169 blah blah), but renewed it.

IPConfig /all gave me an ip address for within the DHCP scope range of the bt wireless router. I opened up internet explorer and google loaded.

The vista default gateway is the same as the default gateway of the router in which the XP recieves, so I know the concept of bridging the connection hasn't inferred that the xp would be a gateway, its simply merged both together.

Have I discovered anything new or is this just another way around sharing internet connections?

Also, does this mean that there is NAT beng utilized to allow my two connections to map to 1 connection for inet access?

I'm studying computer networking at college, in my first year the theory of this was covered but never got to try it and in my second year im really getting into the practical so i was just pretty amazed to see it in action.