If you have a great idea for cleaning up space debris

If you have a great idea for how to clean up the growing problem of orbiting space junk, otherwise euphemistically referred to as "space debris", the Defense Advanced Research Projects Agency (DARPA) would like to hear from you. No crackpots need apply. Actually, on second contemplation, maybe a couple of crackpot ideas would help here, because everything conventional I can think of is either a) unworkable, b) way too expensive, or c) both.

Space debris gets some respect