Exercise! - Thinking about trying yoga

I have been thinking about trying yoga but I have a few questions.

1. Is it really a good cardio workout or is it more like strength training?
2. What videos are out there that are good?

I am looking for something to take the place of my stationary bike once a week. I usually ride 5 times a week and I need to change it up some.

Whether it's cardio or not depends on the type of yoga -- some are fast paced, while others are slower (but still difficult).

If you're looking for more cardio, MTV had some yoga videos out there.