The new back route to the office has two traffic circles, each with a mandatory 270-degree turn, connected by a quarter-mile curve and with minimal construction-only traffic. I love traffic circles. I've been taking the back way in and out just for the circling :).
A friend and I came up with a plan to mapmark RTP-area roundabouts. Probably on a Google Map overlay to share, or maybe something usable in an iPhone.