[techiferous]

Okay, here's an interesting idea. First of all, make sure both of you agree that they owe you money and you agree on the amount. Get it in writing.

Then ask them to pay you a set amount every week to pay down the amount. No matter what their financial situation is, they certainly can pay you something every week. Insist on getting paid something, even if it's just $1! Collect the check in person every week. Email them a receipt with an updated balance due. It's a very visible reminder to them that they owe you money and it's a way that you will at least get some money back!