How to negotiate a roundabout

The Commute By Bike blog has a good article about negotiating roundabouts by bicycle:
Back in 2000 a group of researchers studied how motorists interact with cyclists at roundabouts in Finland, Sweden and Denmark. The study used a “stunt cyclist” and hidden cameras to see how drivers reacted to a cyclists presence. . . .

“The most frequent bicycle accident type at roundabouts has been shown to be between the entering driver and the circulating cyclist.” That has been my experience. I used to ride a route that included the roundabout pictured above and it was always an adventure. I pulled up and if there was any traffic coming around the circle my way I would just wait until it was clear. The danger now became inattentive drivers pulling up for their turn, who could be looking right at you and not see you…
His suggestion for complicated roundabouts at high-traffic times, is to exit the traffic lanes and negotiate the roundabout as a pedestrian. Some roundabouts have little bicycle exit ramps that connect with the sidewalk, for that very purpose.

For simple roundabouts (single-lane) and at times of low traffic, you can certainly take the lane and negotiate the roundabout just as any other vehicle does.