You know what's great about being an uncle? It's getting to be one to another kid. I've got two nephews. My brother could go his whole life giving me the coolest gadgets or doodads for my birthday/Christmas/Uncle's Day (there should be one), but nothing would ever compare to making me an uncle.
It's all the fun of being with a kid who's related to you but none of the responsibilities.
I hope to return the favor some day soon.