I finished the backpack mount today.
I use a kids backback that has a fixed aluminum frame and mount my custom construction on this with zip-ties.

It feels very good to carry that sign with this construction. I can totally imagine walking some hours at a demonstration with this setup.

I carried my kids on austrian mountains before, using this backpack, so i know that it wont hurt my back :)

The batterypack lasts at leat 5 hours with connected WIFI and twitter updates.

We will see about the overall performance in some days..