A while back there was a thread about casita scamps that included a link to a bicycle camping trailer that looked kind of fun although probably not practical for long distances. Just came across this video of a bicycle trailer that the guy built for himself to take to burning man. Pretty much every inch of it has been thought through and used in the most efficient way. I've never thought burning man was my kind of experience but if I were ever going to go I think I'd want something similar to this.
https://www.youtube.com/watch?v=x2EgMCk0sts