A little lower down the stack, I always liked the Evil Bit in TCP, a standard which removes all need for firewalls heuristics by requiring malware or packets with evil intent to set the Evil Bit. The receiver can simply drop packets with the Evil Bit set, and thus be entirely safe forever from bad traffic.
At the physical interface layer where data meets real life, I especially enjoy IP over Avian Carrier; that link in particular is to the QoS definition which extends the original spec for carrying packets by carrier pigeon.