Hmmm... just a guess:

1> First, generate a set of delaunay triangles by using an array of vertices (that will be centers of the regions in the vonoroi diagram)
2> Second, calculate center points for every triangle (by interpolating it's vertices).
3> Then, pass all these points to the algorithm again (points used in step 1 and the points calculated in step 2).
4> Delete all edges and triangles that connect to any of the vertices that were passed in step 1.

So what you have left, are the vertices and edges (conflict lines) that seperate the regions. And that's you voronoi diagram.

I could be wrong about step two; Instead of interpolating the three vertices of a triangle, you could also calculate the center of the triangle's circumscribing circle.

Again, it's just a guess so i cannot give you any guarantee it will work. As far as i can see it should work. I'm into computational geometry, that's why i can tell you this info. I would like to test this hypothesis and write a test app. Unfortunatly school occupies too much of my time, so i can't do that for now.

Hope you can get this working.