You've probably heard of Raytheon's Excalibur (pdf) 155mm guided round. It's "the first precision cannon artillery system for the U.S. Army, Marines and coalition artillery." With a range of 40 kilometers, Excalibur was jointly developed by U.S. and Swedish proponents. It has already deployed with U.S. and Canadian forces and Sweden will field it shortly too.
Accuracy range is 6 meters, and it's guided by GPS and steered by fins on a rotating base, with canards near the nose.
As Excalibur goes from the 1A1 version and LRIP through 1A2 to 1B the main goal is to improve reliability and cost. Toward that end, the nose and base (the parts Raytheon makes to go around the warhead in the middle) are being redesigned to be as simple as possible while still maintaining the same capability. There will be fewer parts and seams and the base will no longer spin.
The 1A1 version cost between $130,000 and $150,000 per round. The 1A2 is down to less than $85,000. Of course, one limiting factor to lowering price on the 1A models was LRIP, which provides no economy of scale. The hope for 1B is to reach a number somewhere in the mid-$30,000 range.