It sounds like several of you are arguing against the position that the Bible contains specific commands on how we (USA or UK) should set up our Criminal Justice system. I wouldn't contest your position on that, because the Bible clearly doesn't contain such a command (i.e. the Bible never states, "and every nation that ever exists shall implement all these laws). It rather describes how Israel, as a theocracy (and later as a monarchy) was to conduct their Criminal Justice system.
But that does not mean that we cannot glean some valuable guidance and wisdom from the various laws in the Bible. For example, when we look at the 10 Commandments, we intuitively recognize that some of the laws are still relevant today. We don't argue that murder, theft, or perjury should be legal. But we do recognize that certain laws were intended only for Israel, such as the laws pertaining to the Sabbath (which was specifically labeled as a "sign" of Israel's special covenant with God). So it's not (or at least shouldn't be) a matter of "cherry picking" (or abitrarily selecting) which laws we think are still valid, but rather studying not only Scripture, but also science, history, sociology, etc. to detemine which laws would still be applicable today.
So the question is: Do we disregard laws pertaining to homosexuality simply because there are other laws contained in the O.T. that obviously don't apply today (such as dietary laws)? Obviously that wouldn't be a wise approach. But rather we should examine whether the laws pertaining to homosexuality were intended for Israel only (in other words, these laws were symbolic of their covenant with God), or are still relevant today, such as the laws against murder, kidnapping, rape, theft, etc. And I'm convinced that those laws are still relevant today, including the penalty that is prescribed for them (execution). And lest anyone should make an ill-informed accusation against me, I also believe that capital punishment should still apply to murder, kidnapping, rape, adultery, and at times perjury (when the perjury impacts someone that is on trial for a capital offense).
As an aside, one act that I wouldn't mind seeing criminalized and punished by death would be "False Prophecy", but I have yet to think through whether such a law would be feasible in a secular society (probably not). It would take care of such embarrassments as Benny Hinn and the like though.