Most every bathroom already has a towel bar mounted on the wall, and of course, the shower curtain rod is often used for the same purpose. But if you need additional hanging and drying space for towels, you may want to consider a stand alone towel rack. With an extra towel stand, every member of the family can hang their wet towels up to dry, instead of throwing them on the floor or in the hamper for an unnecessary wash.
Two examples – I love the look of the wooden one:
Free-standing towel racks pictured:
Left: Organize It All Lohas Towel Rack
Right: Organize It All Acrylic 3 Bar Towel Rack with Bottom Shelf