My hs has always done a trip to Hawaii, but I didn't go b/c of the cost & b/c I was all about my bf at that time (he had already graduated). Instead, I did nothing, really. I had to save my $$ for college since I insisted on going away to get away from my parents.
My friends & I didn't go on a trip after graduation. It wasn't the "thing" to do when I was in HS. But, a bunch of us rented a house down the shore & lived there for the whole summer -- which was pretty common to do.
I've never heard of going on a graduation trip, school sponsored or not. I wouldn't have had the money to go even if I wanted to, so I guess it's good that it wasn't something done in my area.
Re: NPR Poll: Where did you go on your HS graduation
Our school quit having senior trips the year befor emine because a couple of the teachers were having flings with some students.
one pair got married a few years later.