I will admit that in some cases, cracks or cracked versions can be better than serials in that they can change the software for the better (most obvious example is KL). But AFAIK I do not know of a single program which has a limited-time serial system, with the exception of NAV's virus definition subscription service - and once the year on that's done, it's simple just to uninstall it and reinstall it
Lol, well i've seen a lot of progs like that Most progs that are internet-based (browsers, firewalls) are like that. For example, NetCaptor 6.5 asked me to enter the serial every time i started it until i found a crack... same for Zone Alarm Pro, and probably many other progs i haven't tried.