Wear cowboy boots. They're basically pumps for men, and a lot of people find them sexy.
That having been said, I'm 5'7", and I was always intimidated by women who were taller than about 5'4". My wife is 5'2". If I had lied about my height to get more dates, I would have wound up with plenty hot chicks who would make me feel uncomfortable the whole time. As it is, I'd rather only get replies from a few girls I find attractive, who at least won't intimidate me when we go out.
I tried online dating for a while. I tried in-person dating for a while, with girls I met at work (I was a young guy working in the food services industry.) In the end, the girl I fell in love with and married was someone I met by accident and became best friends with. We met over the Internet, but not through a dating website, and I was rather disinterested in dating when we met. After years of friendship, we realized that we had something more than just friendship, and started making plans to meet in person (she's from Canada, I'm from the USA.) We knew each other for about 4 years before getting married, and we've now been happily married for 7 years. While trying to find girls to date, I met some who were somewhat interesting, and who I might have had an okay life with, but the girl I married is so much better of a match; it's not even a contest. Contrary to what Hollywood teaches you, your friends are the best candidates for love; they like being around you, and share your interests and probably your personality.