Bathroom shower curtain rods are not one-size-fits-all anymore, if they ever really were. They come in single- and double-rod configurations, shaped round, square, hexagonal, or even triangular; and, they can be mounted anywhere from wall-to-wall to hanging from your bathroom ceiling, particularly if you have a classic clawfoot tub that is not mounted into a wall or corner.

photo credit: Daniel Greene
They are not even uniformly straight anymore. Shower Solutions from Focus Products makes a curved double-rod configuration, which fits standard or oval tubs five feet long and spaces each rod 2 ¾ inches apart. This set is made of stainless steel or brushed nickel, and the rods are an inch in diameter, with the set mounted on decorator anchors. The stainless steel set is marked as $69.95; the brushed nickel set, for $67.95.
Randolph Morris makes a large number of rods for clawfoot tubs, including a popular D-shaped rod ring fashioned to fit clawfoot tubs 27×66. The D ends mount to the wall and the center of the D arm is supported by a tie rod mounted from the ceiling. The price ranges from $129.95 for chrome to $179.95 for polished brass and $189.95 for nickel.
The same company also makes a half-hexagon clawfoot shower curtain rod, with the ends mounted on a right angle wall to wall and the center section supported from the ceiling by a tie rod. Both the polished brass and chrome versions sell for $97.95, while the nickel version sells for $159.95.
However, you can obtain a very viable shower curtain rod for far less than half the money of the foregoing examples. Sears, for example, sells a Cannon adjustable rod with booted ends that secures by internal tension to either wall. Made of metal composite and painted brushed nickel-finish mocha, the rod is a full inch in diameter and can be adjusted up to forty inches long. The price is $13.95.
And if you like the double-rod style but have a comparable low budget, Sierra Tools makes a double rod that can hold either a double curtain arrangement or towels and washcloths on the outer rod. Each rod is an inch in diameter, extends up to sixty feet, and has simple installation on double-rod brackets. This set is sold at Target for $19.99.