Whatever mood I'm in when I'm changing it usually inspires the picture, quote, or whatever else I put in there.
Now, it's lyrics from a song that I just found and am obsessed with, Cheek to Cheek by Fred Astaire. It's one of the chorus verses. And the picture on the right is how I'm feeling now.
But I'm getting kinda bored with it, so I'll probably change it soon. I get bored with my sigs really quick.
ETA: I forgot to add that I get a majority of my pictures from photobucket.com.
ETA again: I changed mine today. It's inspired by my new obsessive-favorite movie, P.S. I Love You. Plus a line from one of my favorite songs that kinda applies to this movie.