Bill writes in with this excellent homemade weed wacker powered bicycle –

“Whilst travelling south on the Pacific Coast Highway (CA 1) in November of 2006, I happened to stop at the restaurant/deli/convenience store in fabulous Gorda, CA. Up rode this chap on his home-built “moped” and I snapped these photos. Sadly, I neglected to get a photo of Terry, the maker.”Link.