You really haven't lived until you've scraped gravel out of your side once or twice.  I picked up rollerblading as a way to relieve stress and once I started to get really good at it, we started to play pickup games down where I used to live.  I love the speed and the "blood and guts"  part of the game.  It really gets the adrenaline going. 

 

 

 

Also a sweet fun hobby of mine.  I currently am a green belt in TaeKwonDo (ITF), though I have yet to take up classes again since I moved.  I really admire the discipline and self control and perseversance needed to do well in this particular field.  I also find it to be quite calming most days.