Hrm... I'm not too sure on this, but I'm fairly sure only URLs get logged (of course, content sent could be logged as well, but that's a little heavy to look through, plus, could be invasion of privacy depending on where you are). So if you just read posts and stuff on here, you should be fine, unless your employer decides to question why you are on a forum instead of working
As for the titty board, afaik, the images are externally linked. So sometimes you get nice vague urls, but then sometimes pictures are hosted on something like FreeXXXPicHosting.Com or something like that.