Edit, January 2011: also see the next generation of Plush Tux.
As a Labor Day weekend project, Santhosh and I made plush Tux penguins (in honor of our favorite kernel). Neither of us had done a major sewing project before, so it took the two of us about 16 hours to make two penguins.
We obtained free (as in speech) schematics from free-penguin.org. That site is somewhat light on instructions, but the patterns came out very nicely. Each Tux stands (er, sits) about 11 inches tall.