Aligning center of circle to grid point?

[christian ridderstrom gmail com]

How can I draw a circle so that its center is aligned with a grid point?
(I'm using snap-to-grid).

What I'm trying to achieve is a small black dot to put on intersections of 
lines. As the lines are usually drawn between grid points, the 
intersection will also be on a grid point.

As an aside, I'm not using the 'connection' shape because it has such a 
large "boundary" (not sure if that's the word).  If the 'connection' shape 
could have a boundary that's closer to it's actual size I'd simply use 
that.

cheers
/Christian

--
Christian Ridderström, +46-8-768 39 44               http://www.md.kth.se/~chr