You just have to get out there and shoot, nature, people, landscapes etc.
You can also play around with lighting and settings, for example focus on shutterspeed one day. Find some waterfalls, moving objects and try to achieve the sense of motion by using slow shutter speeds. Or focus on composition, challenge yourself to find anything and everything and try to make it an interesting subject. Go out and work on manual focus, turn off auto focus and challenge yourself to shoot everything manually....you get the point.
Everyone gets in ruts or has creativity block, but sometimes its really about just doing something different than what you normally would.
I have some shots on that thread pollyana shared...I'm currently revamping my site so the pics on their isn't my best, I just used them to see how the gallery worked.