Tails

Wire & Delrin

Metal Tubing

Pipe Insulation

Jointed

Pool Noodles

Weight lifting belts

Beanie

Foam

Oversize tails

Standing tails

Canine

Feline

Horse

Dolphin

Unci's tail building instructions - http://www.claws-and-paws.com/furry/non-fiction/uncis-tail.html

Making a tail using a wig (courtesy of Tashta!) - http://www.stripedsmiles.com/CostMakingTail.html

BigBadWolf's method of using PVC and springs - http://fursuits.wereanimal.net/tailmech.htm

Easy tails from about.com - http://sewing.about.com/library/weekly/aa092198.htm