Lately, I've been thinking a lot about the idea of reducing granularity. For example, instead of counting off each arrow in a 20-arrow quiver, you could roll 1d20 every shot and on a "1" say the entire quiver is used up. Or, you could roll a D10 and say on the first 1 its half-empty and on the second 1 its out. Or, you could roll a smaller die (or the same die with greater odds) at a less frequent interval (say, a D4 at the end of the encounter).
Why not do something similar with HP?
For example. Moe the Fighter has 20 HP. That means he can take about 5 or 6 dice worth of hits (6 sided dice). You could instead say that Moe has three Health Levels: Hale, Wounded, and Disabled (then perhaps a fourth -- dead!). Whenever Moe takes a hit, he needs to roll some sort of check with about a 50% chance of success. If he fails, he drops a health level.
You can represent double damage -- perhaps that done by a powerful monster -- by requiring Moe to roll twice on each hit (i.e., he can drop two health levels at once!) or by significantly reducing the odds of success (i.e., he is very likely to lose one health level). You can represent smalld amage by increasing the odds of success.
You can replicate higher HP totals (say, a fighter vs. a MU) either by giving the fighter more Health Levels of HP or by giving the fighter a smaller chance to lose a Health Level (maybe the Fighter needs to roll 3-6 on a D6 to pass, and the MU only passes on a 6).
The advantages to this system are that it allows for more player control -- you are rolling the dice. It also is less granular which has some advantages (reduction of math, etc). There's a more dramatic feeling with each wound, rather than a "circling the drain" decrease of HP. It makes it very clear to see what everyone's HP status is at any given time.
Disadvantages -- it can be swingier. You could get poor luck where the durable fighter that only has a 25% chance to lose a level each check fails the check four times in a row, or you can get a doughty (lucky?) MU that passes four times in a row when he should fail.
OD&D Experience Levels
8 hours ago