Well the problem is that you'll need to find out what the pop culture favourites are in your area. I can give you an example from my life:
This year Big Brother was on TV again and I'd always watched it in previous years (It was a dirty little secret, lets say) but this year I decided I didn't want to waste my time on it. I watched the first two weeks, and that meant I knew most of the peoples names and could guess their personalities through first impressions. After that I never watched it again but when my friends were talking about it i could still join in because i had a basic idea of who was who. This was then pretty circular because they would then fill me in on any new people in the show, any major events etc so then I could progress on to talking more about the show.
I don't know how useful that example is but I like to think that it shows the main thing is getting a basic knowledge and (maybe faking an) interest. You might have to talk about things that don't inspire you to get into further conversation. I don't talk about my passions (music, guitar playing) with my friends that much - we just talk about whats going on in our personal lives.