I absolutely love the simplicity behind using nice strong steel plumbing pieces to build just about anything. You can use it for play sets outside, building book shelves and here in this case for building a nice rustic coffee table.
Great blog with lots of nice photos and a terrific parts list so you can duplicate this same table for yourself.
A couple of questions you may have after reading this post are answered in the comments. So, make sure to read all the way down. Things like cost and exactly how to attach the wood to the metal piping.