Pointing out cultural differnces in high-fives among Warhammer and Warhammer 40k races:

Imperial Guard High-Five: Both participants raise their hands, then cower, snivel a bit, run and hide. Then they surrender to one another. Never mind, there are more where they came from.
Orc/k High Five: One or more participants raise their hands with 2-4 fingers outstretched. Even though they're both aiming for each other's hands, they will invariably miss and hit one another. Then they'll fight for a bit and one will die.
Tyranid High Five: Both players raise their claws and there is a nasty crunching sound.
Tyranid Veteran High-Fiver high-five: Both participants forlornly bump their wrists together. Sobbing optional. Regret mandatory.

Anyone got any other ideas?