I've heard of a way of playing EDH that awards points for accomplishing special feats, such as most damage in one turn, most general damage, most players killed, last to survive, etc.

This seems especially interesting for store-leagues that want to redistribute credit based on various aspect.

Could anyone find me a link to this rules variant?

Thanks!

Ideas include, but aren't limited to (plz make suggestions):
Participation
Specific life point (I'm at exactly 100) or opponent life point (taking an opponent to exactly 17)
First creature with specific P/T
Second player to kill a creature
Attacking for a specific amount of damage
First player to spend 10 mana on a spell
First player to have something of his copied
First player with 6 basic lands in play

You get the point. Again, if you have ideas, feel free. If any of the ideas above particularly interest you, let me know.

Ooooooo....I love thinking about stuff like this.

Richard Garfield often has prizes for accomplishing different "missions" in the game when he gunslings, and what I really liked about his was they did a good job of rewarding creativity without being overly complex. Some ideas along those lines, and picking up on a few of your broad themes, might be:

(In all cases, the first person to accomplish the mission would win the prize, and exact numbers could be fiddled with.)
Overkill: Dealt 41+ damage to a single opponent in one turn.
Just Enough: Dealt exactly lethal damage to an opponent.
Straight Flush: Simultaneously controlled five permanents of the same color with five consecutive converted mana costs (e.g., Rofellos / Eternal Witness / Ravenous Baloth / Ursapine / Silvos).
Good Samaritan: Made an opponent gain 10+ life.
Salsa Dancer: Played the fifth spell on the stack at one time.
Pardon the Interruption: Stopped a combo that otherwise would've gone infinite. (Possibly subjective)
Mana Maze: Controlled 12 different lands at once.

I considered running an EDH side event at a recent vintage event I ran, but decided in the end that I didn't really approve of the concept. We did play out a fairly excellent 2HG game of EDH while it was still ongoing though.

Had I run it, I was going to have a points system, something like:

Last player surviving: + 30 (with degen. combo, only +5)
Eliminated player (each): +20 (with degen combo, only +5, with general damage +50)
Cool play, minor/major: +5/+15 (discretionary - and evidently subjective)
Then some colour specific things like:
Black - killed 3 or more creatures in one turn without a mass removal spell +6; discarded 3+ cards from opponent's hands +6; dug up a creature -2
White - gained 10+ life in a turn +5; controlled 2+ creatures with protection during upkeep +2; played a wrath -2
Blue - played 2+ spells in the mainphase +2; drew 4+ cards in a turn +2; bounced 3+ permanents in a turn (not mass bounce) +5; countered a spell -2
Green - controlled creatures power 10+ during upkeep +3; played a creature with power 5 or greater +1; destroyed 3+ artifacts or enchantments in a turn +5; generated 12+ mana in a turn -2
Red - Dealt 10+ damage to at least 1 opponent in a turn +7; flipped a coin this turn +3; copied or redirected a spell +4; Destroyed a land -2

Haven't given it a whole lot of thought, but doesn't seem too gamebreaking.

Bases Loaded: Control a land, creature, enchantment, artifact, and planeswalker, while having both a sorcery and an instant present on the stack.

Not sure what the points would be worth but here are some ideas,

Carnival Float: Float three mana of each colour before spending all of it. If one of the spells gets countered or fizzles you do not get the points.

GG on Three: Win on turn three. Opponents conceding does not count.

The Controller: Successfully counter seven of your opponents spells in a row.

This is Madness!: Deal 300 or more damage in a single turn.

Now I know my A B C’s: Play the third spell that begins with a consecutive letter of the alphabet. This may span multiple turns. Furthermore if a player adds another spell they get the points not you.

E.g Player 1: casts Shock, Player 2: casts Terminate, Player 3: cast Unsummon.

Player 3 would get the points. However if Player 4 casts Vexing Shusher the points are then awarded to him/her instead. If a player were to cast say an Eternal Witness the letter chain would be broken.