Make a game out of reaching your goals
Go to a yard sale and pick up a cheap board game, if you don't have any "throw away" games at home. Sit down and brainstorm a way to transform the game into goal-completion fun. Use contact paper to cover the old instructions or commands, and write in new ones with a permanent marker. Use stickers, arts and craft supplies, etc., to dress up the game to fit your needs. Then set the game up somewhere out of the way to play on an on-going fashion until you reach your goal.
Use drinking games as a source of inspiration - for example, you might decide that whenever David Letterman takes a sip from his mug during his show, you have to do a set of crunches or iron a piece of clothing.
Create a "Wheel of Fortune" spinner (you can re-decorate an old board game spinner) and spin it every morning to discover your mini-goal for the day.
Set up a "game board" on the fridge and move magnetic pieces that represent various goals ahead one square for every task or mini-goal you complete on the way to the big finale.
If several of you are working toward a common goal, hold casino nights at home or at work, where you bet goal-related tasks (keeping score on paper) and forfeit what you lose. For instance, if you have bet twenty crunches, a mile's walk and skipping two desserts on a losing hand of poker, you have to do everything you bet. You can also write such tasks on poker chips with permanent marker and then claim the forfeits you have in your stash after the game ends during the period between games.
Combine two or more examples for real fun!