http://www.flickr.com/groups/firstgoatse/pool/
I think that's pretty sfw, just reactions of people seeing goatse for the first time.
I would rather see a site dedicated to people viewing the picture of the guy who committed suicide by using a bandsaw.
That said I tend to not think about goatse, girls and cups, etc. I have seen so any things on the internet I am kid of numb to these things. Funny thing is only one set of images make me queasy and it came from a time before the internet. Still remember loading some EncyclopediaCD after an hour of tweaking DMA/IRQ settings just to get the thing to work and I somehow came across...
nothing nude, just a google search of a unique medical condition. I recall it being similar to the 1st and 2nd picture. Picture #3 of the woman is something new to me and creeping me out once again.
spoiler (click to show/hide)
http://www.google.com/search?q=black+hairy+tongue&hl=en&prmd=imvns&source=lnms&tbm=isch&sa=X&ei=LnUPULO6GoTi2gWIn4GwBQ&ved=0CEsQ_AUoAQ&biw=1920&bih=924