(Overcome by Events)

Laser guided bombs were first used near the end of the Vietnam war. They aren't a new technology. They can be very accurate (CEP on the order of 3 meters) but they have some operational limitations, such as having trouble with smoke, clouds, dust, etc.

It seems the military is moving away from laser guided bombs to systems like JDAMS that use a combination of GPS and inertial guidance. If you read the reply I wrote to Robert about CEP, you can find links to articles that discuss JDAMS accuracy and efforts to improve it.

As for laser guided bombs, I don't know this for a fact but I've heard they can use a pulse modulated signal to authenticate the laser source. If so, that might reduce the effectiveness of jamming. The laser source can come from troops on the ground or from systems mounted on aircraft like the one used on the F-117A.