I've been tatting around with zdb for a while now and I've only just noticed that the ZFS developers have a "L33T" sense of humour.

Ever noticed what the "Uberblock" section of the output of "zdb zpoolname" reports? Here's an excerpt from one of my pools:

[...]
Uberblock

        magic = 0000000000bab10c
        version = 13
        txg = 2450224
        guid_sum = 2051813114395829123
        timestamp = 1225469746 UTC = Fri Oct 31 16:15:46 2008
[...]

Noticed what the magic number says: 0000000000bab10c = OOOOOOberbloc = Uberblock. :-)