crack_van has overviews of all sorts of fandoms, the one's for NSYNC and BSB are really good. Links: nsync overview (http://www.livejournal.com/community/crack_van/5882.html?style=mine) backstreet overview (http://www.livejournal.com/community/crack_van/396646.html). As far as concerts go the only thing I can think of is that there's a LOT of screaming and I always brought earplugs, they helped cut out the high pitched shreiking but you could still hear the music fine. Other than that, most of the nsync converts I've been to were huge stadiums of thousands and thousands of people. But when I saw Justin it was a small club show of only a couple thousand, so it was a lot more intimate. Oh an the big boyband concerts are never general admission, there's always assigned seating. Hope this helps!