I'm a big gamer - and it's always nice to get the little "achievements" when you kill 100 zombies or whatever it is. Recently, I've been applying the same reward system to biking for my own amusement.

Some of these achievements can and should be attempted, others are little things that happen to you by chance, some are just for fun, and some SHOULD NOT BE ATTEMPTED UNDER ANY CIRCUMSTANCE

Here's some of the ones I've been throwing around in my head...Feel free to add to the list, be creative and have fun with it!

(Achievement: Description)
Free Spirit: Take an alternate, unknown route on your way home
Mashin' Potatoes: Climb a serious grade on the highest gear
Diaper-legs: Forget to pack a set of underwear, walk around the whole day with your bike shorts under your slacks.
Flyin': Go over 30 mph
Rocketman: Go over 35 mph
Reckless endangerment: Go over 40mph
Show-off: Pass a car when it's not stuck in traffic
OVER 9000!!!!: Burn over 9000 calories/week, climb over 9000 feet/week, or bike over 9000 miles/year
Sprinter: Haul ass to make a stale green or yellow light
Hardened: Get hit by a car
Hahd Baastuhd: Get hit by a car, finish the ride to your destination
Ultimate Hahd Baastuhd: Get hit by a car, the car suffers more damage than you
Rainman: Commute through a rainstorm/thunderstorm
Frosty: Commute while it's visibly snowing
Desert Fox: Commute when it's over 90 degrees outside
Trooper: Commute at least 3 times a week during all 4 seasons
Iron legs: Bike 200 miles in 1 week
Look Ma'! No hands!: Ride without holding the handlebars for 1 mile
Pwnage: pass a road bike, while on a mountain bike. +1 if you were wearing sandals, +2 if you were carrying gear and they weren't
Jitterbug: Drink some coffee before your commute
Boy Scout: Get a flat tire, replace it on the road because you're carrying a spare
Pragmatist: Get a flat tire, call a cab.
Gear-Head: Perform your own bike repairs
Haters Gonna Hate: Zip by a bunch of cars stuck in traffic OR get home/to work in less time than a car would have taken
Gators Gonna Gate: Pass a gator.

Additions:
Clippy: Unclip left/right, fall opposite.
Oooo Shiney!!!: New bike
N+1: Bike acquired
Triple Lutz: Have fallen on ice
Spinnaker: Have had a 30 mph tailwind
Beating to windward: Have had a 30 mph headwind
Double Whammy: Flat both tires at the same time
Litterbug: Lost pump/water bottle/whatever somwehere on the way
Follow the White Rabbit: Chased by a big dog
Tastes Like Chicken: Got caught by the dog
Who Let the Dogs Out: Chased by multiple dogs