Engagement Rings for Men
Not so long ago, men's engagement rings were nonexistent. Traditionally, it was the bride-to-be who got the engagement ring, while men simply wore wedding rings once married. It was also true that the man proposed to the woman, rather than the other way around. Regardless, though, the recipient of the engagement ring wears it to signify that he or she is already "taken," even if not yet legally married, and "engagement rings for men" have become increasingly popular in Europe; slowly, this trend is making its way to the United States, too. Equality of the sexes and gay marriage are changing things.
Breaking Tradition
Although not every couple breaks with tradition, it's increasingly NOT true that couples are following traditional practices when it comes to engagement and marriage. For example, some couples may not want to actually get married at all, but simply show commitment to each other without doing so. These rings can serve a perfect purpose in this respect, in that they can show commitment to each other without having to follow traditional practices.
It's also true that these days, it's not always the man who pops the question to the woman in a traditional or heterosexual couple. Oftentimes, women pop the question to men, such that men become recipients of engagement rings, just as women do. Couples may wish to be equal in that both wear rings during the engagement, to signify a commitment and to show that they are "taken."
Therefore, these days, it's becoming increasingly true that men wear engagement rings, too. Sometimes, engagements can last quite a long time before marriage, and both people will still want this time to be denoted with something special.
With today's increased focus on equal rights for both sexes as well, women may feel that it's unfair that they wear a ring while their spouse to be does not. In other words, it's a way of "equalizing" status for both the man and the woman in a traditional couple.