well, I got some in my Budmail sample... .3gram was included, and i've been smoking that for two days now. Its (as far as I know!) the comrpressed trichomes and crystals from weed, removed from the bud itself by a filtering process...there are threads elsewhere in this forum aboot it, but this is what i know:

the bud is grown and harvested, then chopped and mixed at high speed in a bucket filled with ice water; it is then allowed to strain through a series of filter bags with different mesh sizes (somewhere in the micrometer range, I think) the crystals and trichomes (read: pure freakin THC) are seperated from the plant matter and allowed to dry into a hard hash-like substance; this is then burned in a pipe or bowl (possibly mixed with weed or tobacco in a joint) it will burn clean, leaving a white ash carcass behind; it may also melt entirely, leaving nothing behind but a stoned fool

I find it to be incredibly powerful; if you have ever used a coffee grinder for a budbuster, and you clean the crystals out, and you smoke the crystals, that is almost exactly what the bubblehash tastes+feels like. except the bubblehash will burn steadily where the crystals merely burn and then die. you can probably hoot a fair-sized chunk of bubblehash ( maybe .1gram) for several minutes, with thick white smoke pouring off it the whole time.