1. An awesome shirt.
I don't care whether your writer loves fiction, prose, poetry, or something totally random. Every writer loves the Prose Before Hos shirt by Busted Tees. Score one today. I bought mine a few years ago and still wear it all the time. It's awesome and so are peoples' reactions to it. (Usually, they go "Huh?")
Everyone loves Alice's Adventures in Wonderland. Let the writer in your life show the world this with a Alice in Wonderland tote bag from Out of Print Clothing. Not only is it super fun to look at, but it also makes a great library or book-shopping bag.
3. An awesome book.
Pride and Prejudice and Zombies. No explanation needed.
4. An awesome bottle of rum.
All writers drink. This is scientific fact. If you're a good friend, you'll get the writer in your life a bottle of The Kraken for Christmas. If you're a great friend, you'll help her drink it.