Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you have been placed in read-only mode.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
G
Yes, AFAIK SP has some collision detection although I have not taken the bravery to plunge into it myself either (yet) so I am not sure how it would work...