Useful indeed, but there is a better alternative. Available in the UK are Concept machines. These little babies take an empty cigarette paper, complete with filter (that can be drilled through to stop it preventing the flow of too much green matter I imagine). These papers can be bought for about a pound a box, which gives you about 50 empty cigarettes.

The machine basically packs the tobacco et al into the paper/filter combo.

The end product is a cigarette that is relatively indistinguishable from a regular cigarette, and even looks at home among a regular pack of smokes.