Today on Open Brackets there's an excellent post called "Gender Politics" (alas, no way to link to it directly), regarding the use of gender in various languages.
Mark Twain wrote about German and gender as part of "A Tramp Abroad" (1880), in "The Awful German Language." When I was little, I thought it the funniest thing I'd ever heard, since I grew up in a German-speaking household.

"Gretchen.
Wilhelm, where is the turnip?
Wilhelm.
She has gone to the kitchen.
Gretchen.
Where is the accomplished and beautiful English maiden?
Wilhelm.
It has gone to the opera."

"To continue with the German genders: a tree is male, its buds are female, its leaves are neuter; horses are sexless, dogs are male, cats are female -- tomcats included, of course; a person's mouth, neck, bosom, elbows, fingers, nails, feet, and body are of the male sex, and his head is male or neuter according to the word selected to signify it, and not according to the sex of the individual who wears it -- for in Germany all the women either male heads or sexless ones; a person's nose, lips, shoulders, breast, hands, and toes are of the female sex; and his hair, ears, eyes, chin, legs, knees, heart, and conscience haven't any sex at all. The inventor of the language probably got what he knew about a conscience from hearsay."