One of my pet projects at home has been implementing IPv6. It is not because we ran out of address space, for me that is of no consequence being that like most of us, we are behind a router with Network Address Translation (NAT). But to get familiar with the technology and learn on the different of implementations. I am currently running a tunnel provided by SiXXS in which I provide IPv6 connectivity through out the house. It has been a fun and educational experience.