[throwaway477]

If you have the IP as of now, you may be able to use that as a pressure point. IANAL, but I used this successfully with a deadbeat client. The client had run low on money after I finished an iPhone app for them. They had been distributing the app on the app store, but hadn't made the final payment, which was five figures. They were still paying the Android contractors, who hasn't finished yet. After they stopped returning my calls for several weeks, I called up their main investor, who they needed a follow-on round from, and told him that they didn't own copyright to their app. I got a call back a couple of hours later, they claimed poverty, but that they were getting money real soon. I offered them a one week license for $2000 paid that day. I had to do this a few more times before they eventually paid the balance. They wanted a final copyright assignment letter from me at the end, presumably to show the due diligence people from their investors.