I buy flameless cookers from:

http://evaq8.co.uk/FLAMELESS-RATION-HEATER-Turns-A-Wet-Meal-Into-A-Self-Heating-Meal.html

A few dozen at a time and therefore pay £1.19 or $1.84 each.

I find one cooker will easily heat two of the "Look What We Found' (one is really not enough) and a pack of Basmati rice in a used lightweight Jiffy bag slipped into my jacket pocket to a temperature too hot to eat. The trick is to leave enough time, 18-20 minutes is about right. Tea is boiling water in a flask and teabags for a fresh cuppa.

The whole pack may then be discarded, nothing to take home.

My main use is for a one day excursion to Bisley. This setup fits the bill as it is flexible and hassle free.

But when walking I use a Trangia and car camping a suitcase gas stove. Horses for courses but I found the Trekmates just too far outside the envelope to keep and use, just not value for money or for our US cousins 'bang for the buck'.

Just as a by the bye, I understand a full size shipping container of MRE heaters exploded. It obviously had many thousands of heaters inside and as they slowly degraded the Hydrogen they gave off accumulated and something ignited it. Not likely to happen to the ordinary person though.

http://www.cargolaw.com/2001nightmare_mre2.html