Having recently been on a fun zipline day, this link caught my eye.  That is one scary, and fun ride.  The statistics speak for themselves:

Height: 918 ft / 280 m
Length: 1.2 miles / 2 km
Top speed: 100 mph / 160 kmph

On the much saner side of things, Lafleche Adventures is a lot of fun, I “highly” recommend it.  Oh, that’s soo funny.

I saw the first link on Neatorama.