Cool Unix Features: /dev/full

I've always thought about collecting random bits of useful/interesting/cool Unix features and the like. Before I let that rot indefinitely in a text file in my $HOME, I'll post it in a series of blog posts. So here's bit #1: Everyone knows /dev/null, and most will know /dev/zero. But /dev/full was unknown to me until some time ago. This device will respond to any write request with ENOSPC, No