The Vietnamese use a style of drip filter / press called a phin, which will replace my aeropress for lightness. The coffee produced is short and strong and designed to be had with sweetened condensed milk (which I always have a tube of anyway :))
http://instagram.com/p/aWzIduHTsF/
Requires a smallish cup, and preferably one you can see through (to see when dripping is complete). I need to find a little plastic translucent one before I take this camping. Branded coffee is available in 2x250g bag boxes, and you use about 25 grams a hit I'd say (tablespoon or so), similar to most approaches involving grounds. Obviously you don't need to use the vietnamese coffee, anything with a medium course grind should work.
Now the important part – the whole thing is very thin aluminium, and a solo one like this weighs in at only 50g with a 100ml or so max capacity. They also do bigger ones for group use into a pot for pouring that would probably make 250ml or so (of strong espresso). You could easily cut this coffee with more water if you prefer a longer coffee…
Even looking in a very vietnamese part of town I had to shop a bit to find the solo aluminium ones – group aluminium and stainless steel solo were much more common. The stainless is marketed as being 'better' for some reason (more weight on the grounds I guess, less flavour from the metal too perhaps..), but obviously I had different priorities. Anyway, I found them in the end for $3 each :D
If anyone is interested I could probably source more, but shipping to the US would make it less cheap ;)