I have recently been doing more long exposure photography – several minutes at a time, using neutral density filters to cut the light coming in to the frame. This can give a silky feel to moving water (waterfalls anyone?) and an interesting look to the clouds (which I have yet to achieve as it has not been cloudy/windy enough).
I took this picture on a grey day on Whidbey Island, WA. The exposure was 6 minutes, during which time these seagulls came and sat on the rocks and then flew away – none of which I intended. There were too many people around for me to shout them away. Interesting effect though, a little like very early photographs which were also, of necessity, long exposures.