[morlockabove]

'Laser brooms' are one idea. I think you still have to be able to resolve the debris, but the idea is to end up causing assymetric light-induced thrust on the debris, deorbiting it faster (by heating the prograde side).

Another very 'interesting' idea is deploying a large amount of fine dust on an appropriate polar orbit. Everything intersecting that orbit will be sandblasted, increasing drag; this will have the greatest effect on the smallest debris, and hopefully anything operational in that orbit will be well enough armored or able to dodge the cloud. The dust deorbits quickly for the same reason as the tiny debris (greater surface area/volume). One of the more metal ideas for space debros handling I've heard.