"but limit their lifetime to 5 years in the normal case, with up to 10 years for extraordinarily patents (like mpeg or other more complicated inventions)." I agree - this sounds like a really good short-term solution. And you'd have to make sure new patents at a later date can't be applied back on something like MPEG - and software patents won't be given/ can be revoked if it can be shown that those ideas where already present in circulation at an earlier date.