I've looked seriously at the possibility of a combination alcohol/wood stove, (the Caldera Cone folks have one) but they are just too heavy. Like phat, if I want a fire and it's legal (not very often where I backpack), I'll just build a small fire in an already existing fire ring.

Out here in the west, in areas close to and above timberline and also in more popular areas, fires are usually banned. Mostly it's because of the scarcity of fuel. The land managers want what little dead wood exists in those areas to decay and replenish the extremely thin alpine soils. A wood stove would be no better than a campfire in this regard, since even small twigs are scarce. We also have seasonal bans--no fires even in the fireplaces in car campgrounds--during times of high fire danger, which usually happen during the "dry season" (July through September, although this year's September is quite wet).

In the East, where you rarely have dry seasons and wood is plentiful if not in too great a supply, it's a different story. I suspect that you'd save enough weight on fuel to offset the extra weight of a wood stove.