maps.google.com does this exactly with a few extra clicks: Click "Get directions...

		smokestack on Sept 4, 2013 \| parent \| context \| favorite \| on: Show HN: Find the fastest route via a place maps.google.com does this exactly with a few extra clicks: Click "Get directions" button, click the "Add Destination" link, fill in A, B, and C then click the "Did you mean a different..."