I'm a technology journalist and am frequently inspired by innovative new gadgets and tech trends. Reading news also tends to get me fired up about issues I'd like to write about.
Besides that, sometimes I get inspired observing everyday interactions among people. My short story "Smokers Corner," for example, was inspired by a snippet of conversation overheard out of context on an elevator!
Often I get ideas when I'm commuting or somewhere else away from my computer. My memory isn't great, so whenever that happens I jot it down immediately in Evernote and come back to it later.