Poison is a frequently discussed topic in the OSR realms, as it so neatly ties into the whole Save or Die topic.
I usually find myself somewhere between the two extremes of "carebear" and "killer DM". I like the IDEA of save or die. I like the idea that a character, no matter the level, can be brought down by fate. At the same time, the all or nothing of it can annoy me, both as a DM and a player.
I tend to use poison very sparingly as a DM because I don't find it fun to haphazardly cut down my players. I'd rather they die at the end of a spear than a pin prick.
So, I'm toying with an idea to use in place of Save or Die, at least when it comes to poisons. In a way, it can actually be a Save or Die, but as it deals damage and no auto death, it may fit in better with some styles of play and groups.
At the most basic, a poison would get rated by levels. Most traps would be within a level or two of the dungeon level, so most traps in a 3rd level dungeon would be rated at third level.
Most creatures would have poison rated at their HD, so a 5 HP poisonous snake would be rate level 5.
Poison damage would be 5 x Poison Level in HP damage - save for half. So that 5 HD Poisonous snake would do 25 pts of damage, 13 on a save. That will kill many characters outright if they are level appropriate, especially if they have taken previous damage.
I would also rule the damage takes place at a rate of 10 HP per round until it's run it's course. I enjoy the antics my players come up with to try and save their collective asses, and the time limit built in would lead to one hell of a challenge.
Again, brainstorming out loud.