The AirBag library allows the pixel-precise detection of collisions amongst a list of DisplayObjects (MovieClips, Sprites, Bitmaps, TextFields, Videos, etc.). It supports the exclusion of color ranges as well as a user-definable alpha threshold below which collisions won’t be triggered.
Home and examples : http://cote.cc/projects/airbag
API Reference: http://cote.cc/w/wp-content/uploads/projects/airbag/doc/