• GREAT roundup
• methods of attachment
  • doorknob, hilarious
  • clamp... you could strap the clamp to just about anything, I suppose
  • PVC clamp
  • another PVC clamp
  • pipe clamp, LOVE IT
• full welded version of the pipe-clamp, awesome :)
• super-simple "shelf" version
• pretty simple "hanging pipe-clamp"... I'm sure I could do this in my garage...
• wood
• PVC