yeah but seriously, when Im overseas I dont generally seek out americans. If i wanted to hang out with americans I'd've stayed in america.
That said, bunac is a good idea. the planned socials are ok, I say just stay at a hostel for a while, make some friends, get a flat that way. also, thegumtree.com is very very useful in finding what you need.
"All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity: but the dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible. This I did."
-T.E. Lawrence, Seven Pillars of Wisdom