Was there two weeks ago, love the place, the way we did it was one of those open top bus tours, you just pay for the day and you can hop off and on whenever, takes you all around, Parc Guell, Sagrada Familia, the centre, then up to the olympic village and out to the Nou Camp and whatnot. Go into the market next to Las Ramblas, quality stalls selling everything and anything. While you will get people saying 'watch your wallet' etc. didn't get any problems with it, but don't take that to mean it doesn't happen. I'm rambling now.