Construction. I do it every summer. It's not as hard as you'd think, but it also ain't a walk in a park either. But the best part is that people in construction tend to be great co-workers and the atmosphere is quite relaxed and fun (nothing like collectively howling at passing chicks). The bad part is that working stoned is totally out of question - not because of testing but because you'll most likely fall off a roof or something. Also, you'll get a nice tan, some muscle and a rugged look. Plenty of chicks dig that.
That depends on what you do. If you're laying shingles on a roof I wouldn't get stoned at work, but my step-dad used to pour concrete foundations and he used to go to work high all the time.
Well yeah, that's a given. But from my experience, 80% of work days in construction will include heights, so it's just not worth the risk. Heck, I even avoid beer at work and have like only one with lunch. But even if I wasn't working on a roof, I sure wouldn't want to operate any heavy machinery while stoned. Now, if you're just pouring foundations it's OK, but it doesn't work that way over here. Here you're expected to work at any position, and I did everything from digging foundations to plastering walls to shingling the roof. I'm not sure how it works in America.