Check out this website: http://www.loquo.com – There is a community section named language exchange where you can start looking for people who might be interested in an “intercambio” with you!
There are also many language exchange clubs like the one here:
They meet every wednesday in Baviera, C/ Marina, 241 – Metro: Sagrada Familia o Monumental, Bus 33, 34 – to get in contact with them just email their list at languageexchangegroup@yahoo.es
Dateclubspain: “Whether you are looking for someone special or just want to broaden your circle of friends, speed dating is the best and most exciting way to meet new people. We promise you a fun night out in a cool venue.”
They offer English and spanish speaking events!
FollowTheBaldie.com – Walking and guided tours in Barcelona and suroundings!