Actually tanning helps because a lot of acne is bacteria-related, not just hormone and sebum related. Bacteria is killed just as well by the SUN and tanning beds as peroxide.
In fact if you have B.O., you can lift your armpit to the Sun for a bit and it will help lol.
It's called OZONE.
http://www.understandingozone.com/what.asp
However, I know Accutane and some other acne treatments make you photosensitive, which means more prone to Sun damage, but as long as you're smart you have nothing to worry about.
People are starting to stop fearing the Sun because we are discovering how healing it can be. The areas of the world with a lot of skin cancer, have very little other cancers and heart disease. And no one ever talks about how skin cancer is the most curable of all cancers. But proper Sun exposure can cut your cancer risk by 50%
Some videos from one of my health-heroes, there is lots of other research into it you can find on your own as well.
http://www.youtube.com/watch?v=m5IQwt9ikqY
http://www.youtube.com/watch?v=ZCCwTKhGSGo&feature=related
http://www.youtube.com/watch?v=n82v4tHipWc&feature=related