While this could be construed at a big breach in somebody's privacy, their partner should not be required to guess whether or not they have HIV. Somebody could easily lie to their sexual partner about the disease, and a national registry would be the perfect thing to combat the problem.
Hivlist.Com has a few names, but we need a national registry. If your sexually active you should want a website where you can see if your girl friend or boy friend is listed. Keeping healthy people informed should be more important than the privacy of the infected. There are websites that list a persons criminal record and address and that information doesn't prevent diseases from spreading. Disclosing a persons HIV status should be government mandated.
A plain and simple No. Use common sense, take preventative measures and use caution. Don't do random hookups and if you're that concerned, get your partner to get tested.
Requiring the identities of people who have HIV or other diseases is equal to punishing them for having a disease. Think of how many peoples lives will be further destroyed by this requirement (due to discrimination).
People with HIV are not pedophiles or other criminals who sacrificed some rights by breaking the law. Having HIV is not illegal. If you are worried about a malicious or dishonest person giving you HIV, then you need to take responsibility for yourself and be more selective with your partners, make sure you really know someone before sleeping with them, or simply using protection.
As much as I love the idea of saving more lives, a website like that would invade privacy in a way. For the people who don't have the HIV virus already, it would be wonderful, but for the people who do have the virus, life would be a terrible thing.