I'm not sure why I'm suddenly wondering about this, but I am.
My group did "take the average or do a straight roll" for our first 3E game right when it came out, and we've been doing "roll high-side" for HP ever since then.
What about the rest of you?
Edit: "Roll high-side" would be rerolling until you get one of the higher numbers on a die -- 3 & 4 on a d4, 4-6 on a d6, 5-8 on a d8, 6-10 on a d10, and 7-12 on a d12.
We do that for the PCs, and we also do that for important NPCs. Generics don't get to have high-side HP.