it's only cool until yer nailed. like i said, i've known people who's creative lives ended forever when they got caught. very dangerous territory to be 'cool' in. you really have to know the histories of the images you steal. honest!
ok, this is a territory that is dangerous copyright-wise. be careful. (this is from the world news - "Satan's Skull Found!!!). it's sorta like using 'batboy' or 'aliens shaking hands with clinton' o 'Elvis at 80!' - it's a classic image and well-known. you're safe so long as they never see it used. since this poster is so limited in distribution, you're probably ok, but i've known people who got nailed hard for stealing far less famous stuff to stick on a poster.
yeah, i think it was a designer 'inside joke' thing that jack summerford did to promote himself on a t-shirt at an aiga convention back in chicago. it wasn't a real ad at all, but a promo joke thirty years too late. but if it HAD been to promote helvitica back around the time it was released ('57?) it would have been a brilliant piece of typography. now, 30 years later, it's just clever. time marches on....
hynes - i think you may think i'm talking about 'type catalogs' like that letraset book you mentioned. i'm actually talking about old art dirctor's annuals and old print magazines and poster annuals and advertising books. anything that had high-end 'graphic design' featured. study they way they organize the type and how they infuse the letterforms with hidden meanings that reinforce the overall message, the simple placement of a word or the weight of a body text can end up getting the whole message across. a LOT of brillant stuff to study an learn from.