My last job offered each employee two "Sunday fundays" a month... Basically we could pick up to two Sundays each month to go have fun on the company's dime, up to $250 (each sunday). You couldn't buy any goods with it, but you could go do whatever you wanted: nice restaurant, skydiving, kayaking, take friends out for drinks, etc. You just had to take pictures and were expected to write a few paragraphs about what you did.
It was a great perk. Essentially nobody really made full use of it (the full $500/mo per employee), but it was always great to have the ability to do so... Sometimes you'd just be out with friends for a big brunch and realize, "oh, hey, it's sunday" and pick up the tab for everyone or list all your meals on a Sunday while out hiking the Bay Area with friends.
