In our school, we are always warned to stand up to peer-pressure when it comes to drugs and crime etc. usually it's just the idea of people following along with the crowd to fit in, though it's hard to actually 'minimise it's bad effects' as it's mostly up to the behaviour of the 'group leaders', which everybody else then copies. It seems to me that there are four social statuses that you can have in school within a peer group, either you are an outcast - you do what you like but everyone ignores you so you'd probably do what you can to fit in anyway, or a leader - you do what you like within certain 'cool' boundaries and everyone copies, or an average follower - you fit in completely with the crowd and is accepted, or occasionally you can get away with doing/refusing what you like (like me) and still be accepted because you are so weird/eccentric that you're almost cool (at least that's what a friend told me!). This basically means that most people are subject to peer pressure and have to be quite strong willed to resist it, however, I feel that perhaps peer pressure has far more influence when a person is younger and maybe less opinionated, at least amongst my friends we seem pretty laid back about what everyone does.
Oh yeah, I just remembered, to see a good example of peer pressure refer to Lord of the Flies by William Golding