I've found this plant to be very interesting, I thought you guys might be interested as well.
besides its large, and invasive tendencies, it is also very toxic. I think this would make a good hedge to go around the yard, don't you?

Giant Hogweed is a phototoxic plant. Its sap can cause phytophotodermatitis (severe skin inflammations) when the skin is exposed to sunlight or to UV-rays. Initially the skin colours red and starts itching. Then blisters form as in burns within 48 hours. They form black or purplish scars, which can last several years. Hospitalisation may become necessary.[1] Presence of minute amounts of sap in the eyes, can lead to temporary or even permanent blindness. These reactions are caused by the presence of linear derivatives of furocoumarin in its leaves, roots, stems, flowers, and seeds. These chemicals can get into the nucleus of the epithelial cells, forming a bond with the DNA, causing the cells to die. The brown colour is caused by the production of melanin by furocoumarins. In Germany, where this plant has become a real nuisance, there were about 16,000 victims in 2003.

I wonder, has anyone ever had experience with this plant?

Here are a few related links:
http://en.wikipedia.org/wiki/Giant_Hogweed
http://www.youtube.com/watch?v=KaV2jwNT0MQ
http://en.wikipedia.org/wiki/Furocoumarin

I've attached some images of it, and its effect on the skin.

I think the actives would dissolve in acetone since most of the compounds have ketone groups and are cyclic ethers. So acetone and alcohol should work. the only thing I would be worried about is you dried the plant material maybe some of it would get oxidized, and if you were to heat it maybe some of it would polymerize, especially if they were in acidic or basic conditions.

Ho ho ho, excellent idea, as long as seeding is controlled.

It grows like Y.pestis in a middle england slum, and once it gets started, it is a bitch to get rid of, they sprayed the forest near me for several years to eradicate it, killed a whole bunch, but it came straight back.

Its an umbellifer, with a LARGE flowerhead (a foot or more accross), and produces masses of seed per plant, once you have one that survives, you will get more, and more, and more, and......

It got me once when I was younger, I was aware of its properties, and avoided it, just obviously not quite carefully enough one time, and got what looked identical to a black haematoma looking blister on my leg.

Hm, how about alternative nasties, such as tropical nettle species?
Although who is going to want to plant bud outdoors here anyway? it would probably turn out absolute crap in our climate, and besides, sure its illegal, but so too is a large outdoor pot grow

For where outdoor ops are practical, I guess how nasty one is prepared to get (and come clothed and equipped to deal with safely) would be dependent on how much one was growing.

Some of those are really vicious, Laportea, Urera, and Dendrocnide species in particular, some can hurt like hell for a couple of weeks, the US species Cnidoscolus stimulosus, spurge/bull nettle has a reputation for inflicting quite a lot of pain, but isn't the 'several hours later you die screaming' kind of thing, but it isn't large enough either to provide the coverage a dense, tough and woody thicket of Laportea

I'd probably go with Laportea sp. Dendrocnide, some are 40m tall trees, Urtica Ferox, a member of the actual stinging nettle family, native to new zealand perhaps, although there is one recorded fatality from contact, apparently from somebody who blundered into a large patch of it. Dendrocnide is apparently capable of killing large animals, the wikipedia mentions horses! some of these tropical stingers are as nasty as plants get, something along those lines got to me on holiday in the middle east and oh jesus did it hurt.

That is one of the plants I would be interested in growing, but it isn't particularly common or easy to get is it?