The "Utah teapot" is an iconic 3D graphics model made by hand measurement of Martin Newell's teapot in 1975 so it is now a 40 year old model! It became so popular mainly because Utah distributed it on the internet (Utah was the 4th site on the ArpaNet so they were already used to it) and so it was the only model most people had for some time. The real teapot is on display in Mountain View and details can be found at wikipedia. Because the teapot was manufactured, you can get one of its cousins. They are occassionally for sale on ebay and come in two sizes, as this screenshot from an ebay listing at the time of this writing shows shows (it is selling the big one for $119 and searching for "Melitta Teapot" will show various types including some of the right shape when you are lucky):
I am guessing the smaller teapot is the size of the "real" teapot but I don't know (Newell was a married grad student at the time, and it was pre-Grande size drinks).
Here's the one I own, with some money for scale:
My real agenda for this post is to ask who has the best model for the teapot? The classic one is not solid and I know many people have done solid models, but I don't know where to get them.