yeah, you basically get assigned a country and a committee, and you go and pretend to represent your country. my school has a really active team so it was easy for me to get involved. you end up going on a fair amount of trips, and if you continue, or even start up in the college level you can go all over the place. my friend for example is on william & mary's team and he just went to a conference in quebec and is going to singapore in a few months.
if you are interested in politics or international issues at all i highly suggest looking into it at some point, it's lots of fun