more commonly used is ECDSA, which is not patented.

Don't travel to U.S territories if you're wanted for U.S crimes.

The idea above sounds well thought out, but it might require a call home detection method. I've been thinking that software updates can be made to exclude known cracked serials, without changing the software version number, therefore making it more confusing for pirates to obtain the correct crackable versions? In a more primitive way I was going to suggest flooding p2p sites with bundles of "trial version + broken serial". In order to give the torrent some credibility the serial could appear to work for a month? In my experience I have found that repeated failed attempts to crack a piece of software only make me lose faith in the crackers and crack sites, my faith in the actual application remains intact.

I believe the view above is a little biased. Lots of people pay for software, just not many slashdot users! Some basic resilience to disassembling/debugging tools like Hopper Disassembler, Ollydbg, Immunity debugger will slow down the cracking process... (although I have no idea what this protection would look like). I suppose there is a balance of the effort you put in to protect your program vs the protection you get, but just because a window can be broken it doesn't mean there is no point closing it.

I agree with this

I will admit that I basically never pay for any software, and will often attempt to crack a free trial myself if I can't find a working serial or keygen, but recently I have bought some apps from app stores. It's hard to say why, but I think I like the convenience of payment, the low prices, and the reassurance that the app is vetted and not going to transmit my passwords to nigeria.

exactly!! While it's all very well spending millions of dollars on a MRSA vaccine, hospitals continue to neglect that washing their hands would do the same thing. "£2.99 handwash kills MRSA"