http://singletrackworld.com/forum/topic/ghetto-tubeless-inflator-total-cost-9p
The 9p ghetto compressor is easy to make and works like a charm. A little blu-tak around the holes helps it seal better if necessary. Removing the valve cores also makes it more effective. Mine seats tyres at 40psi with the cores out.
I use schraeder valves on duct tape converted 719s, the cores are easily removed/replaced and fluid top up can be done through them without disturbing the precious bead seal. Loosening the valves to let the bead sit around, rather than on the rubber really helps, as does building up the rim with a few extra wraps of tape. Not only will this help inflate, it reduces burping due to snugness.
I’ve seen a fence sprayer pump thing used as a compressor but it didn’t seem as good as the 9p wonder due to the flimsy, built in handle.