Are "poppers" legal in the us? if so, which are safe to use before anal sex (if any). what is the best recommendation besides condoms for gay sex?

Not a good idea: There is no law that I am aware of that bans "poppers". Nevertheless their use can be dangerous and in some cases cause death. An over the counter lubricant (not Vaseline) with a condom and a loving relationship is the best way to enjoy sex.

Depends . . .: I believe there are different types of poppers eg nitrites (http://en.wikipedia.org/wiki/Poppers), so I can't comment on the different versions. However, I wanted to point out that we don't recommend using PDE-5 inhibitors such as Cialis, Levitra, (vardenafil) Staxyn & Viagra in conjunction w/nitrites & nitrates as this may lower blood pressure excessively causing one to pass out.