I've thought about a really simple way to handle wounds:
Definition: Wound - the character has taken an injury severe enough that it will take time to heal. A character with a Wound has his maximum healing surge rating reduced by 1 per wound. If the character is at full healing surges when he takes a Wound, he loses one healing surge.
At the end of each day, he may make an Endurance or Heal check to recover from the Wound, with a DC equal to 18 + 1/2 the character's level. Another character may also make a Heal check, substituting it for the Wounded PC's Endurance or Heal if it is higher. A character can only roll a Heal check for Wounds per day per tier, whether they use it on themselves or others.
If a character is reduced to 0 healing surges by Wounds, they slip unconcious until they have at least 1 healing surge.
Aquiring Wounds - If a player is bloodied during a fight, then after the fight they make a saving throw. If it fails, they take a Wound. If a character is dropped(0 hp or less), they take a Wound automatically. A PC can't take more than 1 Wound per encounter.
Think I'm going to implement it in my 4e game. Simple to track, wounds persist, sometimes for a while, hindering the characters enough to make them worth watching without requiring tracking of additional penalties.
Also makes the Heal and Endurance skills useful to invaluable...