I recently put together a timeline for Senator Hillary Rodham Clinton's changing views on the Iraq war. In 2002, she voted in support of the war. In 2006, her language was a bit non-committal, as far as setting a deadline to get troops out of Iraq. Now, in 2007, she's firmly set on getting troops out of Iraq by some deadline. The goal of the timeline is to show this change.
Here's the important lesson I learned during this task -- even though it's easy to put a timeline together, it still has to tell a story. Think about the purpose of the timeline. Usually, you want to show some change or progression over time. The tinting on the above timeline is for events during which Senator Clinton shows a definite change in her stance. The hope is that the reader keeps going left to right.
If you don't keep the story in mind, the timeline is no longer as useful. It's just a bunch of text arranged in time order, which is sort of what the above timeline looked like after my first jab at it. I put tinting on the events i.e. the things that weren't quotes from Mrs. Clinton. In retrospect, such tinting plainly defeats the purpose of this particular timeline, which went with a story that discussed the change. Duh.