I thoroughly enjoy recess. Whether it is outside or inside, I'm a huge fan. Typically I have kids in my classroom throughout each recess. I have kids on computers, finishing homework, doing research, or doing a myriad of other things. If I am in the room, kids are welcome. Some teachers don't believe in that, and that is their style (not to mention right).
When I get the chance I like to get outside for recess. During student teaching, particularly during the term where I was observing and taking classes, I would head outside to play on the playground. I actually brought my soccer ball in as well, and we'd often play soccer games every few days. You interact with kids on a different level, and they see you at play. Additionally it creates a safe place where kids feel like rules will be enforced, and everyone has a chance (not always the case otherwise).
Today I got out for a game of capture the flag. The game has been the talk of Fifth grade since early in the week, and they'd talked one of their previous teachers into playing. They'd asked me all week, but I wasn't able to make it due to other classroom things I needed to take care of. Ahh, but today was the day. Lots of fun running around the frost covered tundra. Kids are so excited to see their teacher running around just them they are. The joy of tagging your teacher, and saying you got him is palpable. It was a great time, and something I'm banking on trying to get out for (recess, not just capture the flag) every other week.