IPv6 addresses are statically allocated (well, in the IPv6 proponents' designs - in reality, we may end up with DHCPv6 and the like), but almost always provider-allocated (PA), not provider independent (PI); so you'll have to give it back to your ISP when you switch.
This is a good thing, by the way; PI space consumes memory on the backbone routers (they can't just send it to your ISP, after all - the whole point is that you can take it with you). Of course, PA space is just part of a larger allocation to your provider.
In other words, don't get the tattoo.
