I'm a big fan of following trends and have several sites that I keep a tab on to know what the latest trend is. I'm not into following fashion trends, but love to know about new products and services, sites that offer a unique new service or an old service but in a new way and so on. The best site for trends is Springwise.com, which I have been reading for several years now. I am also a member of their sister site Springspotters.com where you can write in about new trends that you have spotted. For a curious mind, it's a fun way to keep up with what is going on across the world.
I really love the kind of trends that are spotted on Springwise, since they are all very useful things that all of us can use in our daily lives. Their travel trends are simply super and I have used a couple of them. I also recommend their consumer info related trends such as moving services, taxi services, parking, errands and so on. Check it out and you'll be hooked too!