This type of stretching is quite effective and has been around for a very long time. It works best for some areas (hamstrings for example) if you have a partner to help. I use it in the office sometimes for certain conditions.
AIS (Active Isolated Stretching)? Sounds like the same concept, but you hold the stretch for about 2 seconds. This has been the core of my flex program for about a year and a half now (in addition to some yoga). Check out "The Wharton's Stretch Book" by Jim and Phil Wharton.
It's the most effective stretching technique. You need to be careful with it, but significant flexibility gains can be made with it. - "Yeah, no one likes a smartass, but we all like stars" - Thom Yorke