I have just come back from Barcelona and I don't think I have been anywhere else where I felt so safe; and I am quite the worryworm when out of my own environment!
I just took the usual safeguards. One card and E100 in the hotel safe, the other in a money purse under my shirt. Just kept a small amount of money in my handbag.
I loved Barcelona, much better than my expectations, found the people to be very friendly, helpful and polite. (But not alot of English). Didn't see one junkie - just one or two eccentrics who seemed to be happy living on the street.
Loads to do, be sure to visit the Poble Espanole, Art Gallery, Chocolate Museum (free chocolate), Maritime Museum and lots and lots more. The Zoo is the best I have been in.