To all you 29er's out there!

My favourate, but they dont do one for the 11 speed hub yet. Classic bar-end shifter desgned to work with internal hub gears.
http://jtekengineering.com/jtek_bar-end_shifter.htm

Not sure what your gear set-up is. But have you looked at the JTek site?
I have the DA bar-end shifter/ midge bar set-up MacB mentioned. I really like it. It has a very positive feel, and I can shift easily even in lobster style gloves.

holdsworth's geniuses are working on a method so that my sram i9 shifter can be bar ended on my midge- will keep updated...

This is only my opinion but I think it's worth remembering that a bike can be quite intimidating to walker when flying along so care around walkers and slowing right down is worth it. I presume you know the legalities of where you can ride off road (basically byways and bridleways plus some other designated area like some parts of private forestry commission land like on the south downs but no legal right of way on footpaths).
I remember struggling with this when I lived in Oxfordshire. The local land owners could'nt stop the ramblers, but could stop the cyclists. So they did, without any good reasoning.

In Norway cycling is as legal on footpaths as it is on the road. Which theoretically means you can ride where ever you want. Bikers for main part, steer clear of popular walking routes though. Its pertty clear which areas are more for pre-dinner strolls, and which are more open to cyclists. There are loads of well maintained trails (partialy graveled) further into the mountians, where you can ride. A few hardcore MTB'rs I know use the antena maintainance roads, which basically point straight up to the highest local peak, and are rarely used.