[paulie_a]

The post office has/had one

[xxpor]

The DOD has like 5 or 6!

[takeda]

well since DoD started the whole Internet thingy that's not that surprising, but yeah they were extra wasteful.

[ms4720]

Loop back address, 127.0.0.1, is really a class A block, 127.0.0.0/8, that only uses 1 address

[MertsA]

You can use anything from that block as well and there are situations where you might want a different loopback address or multiple loopback addresses. /8 of the public address space is massively excessive though.