One concern of many who consider a rain barrel is the bright color and "industrial" appearance of the barrel. You can alter the appearance of a barrel by painting it or adding a decorative covering.
To paint a barrel, clean and lightly sand the outside. You can then add either a spray paint specific for plastic or a latex paint with brush. One color or fancy designs: the possibilities are endless. See this website for several creative barrels in Kentucky.
The decorative covering seen on the right can give you an old-fashioned-barrel appearance and is easy to assemble. Take 14 wooden fence pickets and cut them as long as your barrel is tall. Purchase 6 inch flashing and cut them into three strips that are 2 inches wide. Lay the pickets in a row (separated by an 1/4 inch) and attach the flashing. You can then attach the two ends and slip the covering over the barrel. Wooden coverings for the overflow and top can also be made from pickets.