http://www.youtube.com/watch?v=2gstaiVGqkk
Check out this guy's video on collision, this is one of the main ways that most members do collision. it's easy to implement and works for cubes rectangles and squares pretty well. of course if the object was to be circular it would work much better since it is based of the objects center point and of course a rectangle and cube/square do not have a perfect radius.
If you are stuck on a project, check out the tutorials I made here at this link:
http://alice.org/community/showthread.php?p=36778#post36778
There are lots of tutorials on it so far, including some youtube videos, check it out
Or..
Go to my youtube channel to check out my alice 2.2 tutorials I have there..
http://www.youtube.com/user/sfunk1992?feature=mhsn