I am not a fan of hormonal birth control methods.
Thus, the diaphragm.
It is a good alternative, free of side effects. Like other barrier methods, it has to be placed in before intercourse, but can be worn up to 8 hours before, and suggested to be kept in for 6 hours after. It was great for me for the last two years, since it kept my body free of unnecessary hormones that caused yucky side effects (nausea, headaches, random bleeding, weight gain, moodiness, acne). I also rate the diaphragm way above condoms because once its in, neither partner should feel it. It stays so high up inside, against the cervix, that only the long and proud man can reach it - even then it is not a bother to either partner.
BUT, i admit that i'm not totally satisfied, because it does not allow spontanaity, it requires that the woman insert it before getting down and dirty (not a big deal, but can interfere with the pleasure of initial entry), it does have an average of 16% failure rate with typical use. In addition to the worry over becoming pregnant (i already have two beautiful children) I am tired of feeling like it's my responsibility to get up out of bed (assuming we're even at home) every time we're in the mood, to go prepare myself. It takes something out of the experience for me.