I think that prostitution should be legal in the US. If anything, sex for cash is a moral issue, not a legal one. Two consenting adults who agree to exchange money for sex in private shouldn't be prohibited from doing so, especially by the government. If prostitution is organized and regulated (like mandatory health checks, etc.), then I don't see what the big deal is.
BTW, this is, of course, in regards to the whole Eliot Spitzer prostitution ring bust. (International readers... he's the governor of New York.)
UPDATE: Interesting informational website summarizing the main issues of this debate: Prostitution ProCon.org.
UPDATE 2: Okay, I may have had a change of heart. Hillary Clinton on legalizing prostitution:
"I do not approve of legalized prostitution or any kind of prostitution. It is something that I personally believe is demeaning to women. I have worked against it and I have certainly taken a very strong stand against what happens in many parts of the world where young girls and women are forced into prostitution against their wills.
I understand Nevada has a regulated system and it is within the authority of the state. So that is not a federal issue that we will have any role to play in when I am president. But I would obviously speak out against prostitution and try to persuade women that it is not --- even in a regulated system -- necessarily a good way to try to make a living. Let's try to find other jobs that can be there for women who are looking for a good way to support themselves and their families."
Even though it's contradictory to what I wrote earlier, I have to say that I agree with her.
I can see both sides of the issue, I suppose.