1. This material is easily accessible, 2. easy to use, 3. has a great aesthetic, 4. can be used for a variety of projects, and best of all 4. you don't have to be a welder to throw together a quick table frame for your projects..
The only downside to this material is cost, it's not the cheapest thing to use, even a small project like the larger dolly above has a high material cost. Extra piping and embellishments can drive up this cost and translate as steam punk; which for me is just another reason to keep the design simple.
I've seen a lot of really over done wardrobe units with superfluous arms for various uses, but personally I like to air on the side of simplicity. Here are three of the ways I personally like to use gas pipe for custom clothing racks and table frames.
USE.01//Clothing + Shoe Rack
Shoe rack and jacket rack, constructed out of a heat treated pallet and black iron gas pipe [castor wheels for easy transport].
One of the ways to build a great frame for a table. Pictured:Black Iron Gas Pipe Table Frame and Marbled Table Top.
USE.03//TWO TIER CLOTHING RACK/DOLLY
A simple two tiered black iron clothing dolly, [castor wheels for easy transport].