Here's another cool secret I use all the time...really good for training too...
If you don't have glasses with orange or yellow lenses--get a pair. I call them my "sunny day" glasses. When the world is dank and gray, putting on regular sunglasses just makes it even more depressing. Riding 3, 4, 5 hours in the murk is no fun. Put on the orange or yellow lenses and--voila--instant sunny day! It really tricks the mind into feeling more upbeat.
My last six hour ride before my 2006 Ironman was done on a very gloomy day. My husband, who rode with me, was so unmotivated by hour 3--sinking deeper into the morass of blah. He was wearing regular sunglasses, which made the world even darker. I was fine, and kept telling him because I thought it was a sunny day. He tried on my orange lenses, and got a pair the next week.
Cheap, rimless ones from Nashbar work fine. You don't use that that often, but when you need them, they're a great item to have.