U.S.A.
Social trading is also a good option for US citizens. However, be advised that in order to join a social trading network based in the U.S., your account must comply with non-hedging and FIFO rules.
ZuluTrade’s international website also accepts US accounts, and have special non-hedging features available for them.
eToro is also open to US traders but these can not register through the international site, but MUST register their account on www.etoro.com/usa/.