When it comes to niche social networks, I am usually not a fan. That said, I do like Athlinks, a social network for endurance athletes. The reason being, they do a great job of compiling previous race times and photos. I inserted my name and age, and the system did a really good job of compiling past race history. So if you have ever competed in a 3K, 5K, trithlon, half marathon…they will find your past races, store your results and allow you to compare future results. Other than that functionality, I will probably not use the site, but I do love that function.