wheel spacers


hiya, i like the look of a chunky 4x4, and have been considering buying a set of spacers to bring the wheels out, as this would be cheaper than buying 4 new wider tyres. what i'm worried about though is putting extra strain and pressure on the hubs etc. as anyone had experiance with spacers and what are the pro's and con's. would it cause any problems and what about any long term damage?