Anyways here's a video talking about how to access this node and some basic ways to use it (namely for sticking stuff onto a user-defined point on a curve).
A quick tip, which is in the video and which is a reiteration of info I've posted before. . .
Rather than using:
createNode pointOnCurveInfo -n "name";
which will give you node, but leave it hidden from view in the hypershade, I prefer:
shadingNode -asUtility pointOnCurveInfo -n "name";
which does basically the same thing, but flags the node as a "utility" and thus puts it under the Utility tab in the hypershade. Just thought I'd point that out again.
Maya/Rigging: Attaching objects to a curve (using pointOnCurveInfo node) from zeth willie on Vimeo.