I know that up until the early 90's people at my school pinned as well as lavaliered, but I never hear about people from my school getting pinned anymore. Some guys still lavaliere, and my boyfriend gave me his LXA lavaliere at my graduation party on the day I graduated from college (it was very sweet--my whole family and many of my sisters were there watching! All the non-Greeks were confused, and wanted to know if I was engaged). After that, I could wear his letters sweatshirts or anything that had letters on it. I put his letters on a chain with my own lavaliere, and I still wear them sometimes.
I know some houses have to "vote" on the girl, but since he was technically an alum already, he just decided to lavaliere me. I have also heard of some guys getting completely abused by their brothers after giving thier girlfriend letters, but nothing happened to him! One of my sisters had gotten lavaliered by one of my boyfriend's brothers just a few weeks earlier, and we were so excited! It was a very fun time......