I'm probably nearing the end of the decent parkour stock available on YouTube--after all, the number of traceurs (parkour practitioners) is relatively limited, especially compared to, say, the number of guys who can dunk a basketball or score a totally sweet goal.
In any event, check out these: video one, video two.
Stateside, some traceurs are doing interesting things in the Denver/Boulder, Colorado area, as discussed in that New Yorker article linked below. Here's a video of them on CU-Boulder's campus, and here a larger group performs in downtown Denver's Skyline Park. Also, a solid video of Colorado local, Ryan Ford, I believe, at Red Rocks six months after suffering a serious injury.
Anyone in Denver might be able to check out the local group on Wednesdays 1-4 p.m. in Skyline park, according to this site, and again on Fridays at 3:30 p.m. on CU-Boulder's campus at the Engineering Center (near the bottom of campus). For their full schedule, go to coloradoparkour.com, where you can also find information on their weekly classes in Boulder.