UV exposure will give you cancer!
It's a government verified carcinogen, and if you voluntarily expose yourself to it in order to be "attractive," you need to re-evaluate your actions. Since summer's here, this fact needs to be emphasized towards people who are planning to sunbathe or otherwise tan. Skin cancer doesn't just happen to people who don't use tanning lotion, or people who get bad sunburns, or people with fair complexions, it happens to anybody who is exposed to too much ultraviolet radiation.
With this in mind, suntans no longer look attractive. That is, when I see somebody who is deeply tanned, I automatically think "Aha, a stupid person!", and any sexual attraction I may have had towards them goes away. People who do use sun block (SPF 20 or above is best) will be a normal color, and I can tell they care about themselves and their future, thus making them more attractive.
If this meme is spread, perhaps some day everybody will react to people who tan the same way I do, and they'll stop. Score four points for sanity, woohoo!