If you don’t fancy the idea of getting the bus or the metro, then a taxi is a great alternative. Official taxis in Barcelona are yellow and black and have a green illuminated light on the top, which indicates whether it is available, or not.
A 15 minute journey will cost you about €10.00 and a licensed taxi has to charge you what is on the meter, so you can be sure that they will not add a bit extra just for the hell of it. However, if you are carrying more than the usual amount of luggage there could be a surcharge, but all the rates will be on display in the cab.
Tipping is welcomed, but don’t feel that you have to. If you would like to give a tip, this is usually between 5 and 10% of the fare.
Before you hail a cab in Barcelona, be aware that much of the city centre is pedestrianised and so walking, the metro or the bus may be the better choice.