Sack Pump Nozzle

My original [Exped Sleeping Mat](http://www.exped.com/new-zealand/en/product-category/mats/downmat-7-m) had an awesome feature - its bag could be used to inflate the mat in seconds by attaching it to the mat's air intake and using it as a pump (see below for a more detailed explanation).

Unfortunately, that mat died - and its successor replaced the clever and light-weight bag/pump mechanism with a bulky and tediously slow 'built-in pump' system.

This thing attempts to resurrect the ori