Here's a sample of some particle streaks that I made in After Effects using Trapcode Particular. They were for Univision's Upfront presentation in 2011.
This was the opening sequence of the event, almost like a countdown with musical instruments tuning up before the show was about to start. Each shot was to be contained in one of 8 screens, and the trail was designed to lead the audience across the stage to the next screen, and have the trail die off in the next frame. I couldn't really show that without the actually set up, so I just combined them into one video.