I've worked in the past, and currently work, in a company that serves porn up to paying members.

I've never encountered any discrimination from other employers, in fact, most seemed to think something like 'Great, he knows how to build stuff that handles high-volume'.

As for being exposed to porn, at least in the positions I've held, there wasn't alot of it. (no more than your average web-surfing trip would bring you in popups/ect)

I mean, sure, there are gigs and gigs of it on the content servers, that I could go digging through if I wanted, but it's not there in front of me all day, most of the time I see a text editor.