Beluck,

Why don't you use any escrow service? It guarantees you will receive your payment after the work is done. I am a programmer myself and also experienced bad clients. Now I am a bit selective about clients, prefer talking with them before taking the job. I usually give to a new client a choice to pay with escrow service 15% more (it's a commission of rent-a-coder), but after the work is done or prepay 100%. If the system is quite complex (several thousand $) I make a timetable with work milestones and payments. Would be interesting if you and other coders here share their thoughts about how to protect our work.

Wookey