My commute is just 15kms, though, so just water for that.

On my longer rides, I like a nice cane sugar cola, usually at the 70km mark or so. If I can't find one, I'll drink Coke if I want to wake up a bit. I started doing this when I read Parkin's descriptions of doing so in professional races in "A Dog in a Hat". Yeah...I'm a dork.