In my excitement of bike-tinkering and cannibalizing of parts to build up the travelers-check, my Long Tail Trucker was left without a crankset and front derailleur. Fortunately I had an old truvative crankest and even older shimano derailleur, but the derailleur was a top-pull and not compatible with the Trucker's down-tube shifters. The pictures bellow chronicle rerouting the cable by repurposing a spare cantilever brake hanger mounted to the seat-tube at the water bottle cage brazon. I also used a brake cable for added strength. Repurposing parts is much more fun, economical, and good for the earth, than buying new parts.
Fit in some cable housing, and duct-tape it in place: