Whilst scanning flea bay I noticed a rather lot of front 3 speed shifters available and that got me wondering....
...If you could use a front 3 speed shifter on a rear mech?
You could create a custom 3 speed cassette using an old cassette with say with 11, 18, 32 cog sizes giving you a downhill, flat and uphill 3 speed bike 
The tricky part I guess would be getting the distance correct between the cogs to match the pull of the cable.
Totally pointless I know but it could start a whole new niche!!
