Good reflective gear for running/biking??

Do you have any suggestions or recommendations for decent gear to run/bike in at night. I'm looking for something that would be very lightweight, at least water-resistant, and breathable of course.
I saw a cool jacket the other day that had detachable sleeves for those warmer workouts. I just didn't know the brand, or if it was worth dropping $75 on.

Anybody get theirs from an online retailer?

Thanks!
~B