[onetwo_threefour]

Send your co-worker an email every morning claiming credit for some revolutionary idea like scissors, the internal combustion engine, post-it notes, email,or the like by describing it as you would a patent.

For example, "Hey, yesterday I came up with this great new idea, you take two blades with handles at one end and attach them in the middle with a hinge so the blades can slide past each other. I think his would be a great idea for a portable paper-cutter! Why don't we suggest this to the boss."

The most hilarious outcome would be if she was too dumb to catch on and actually did so, but even the passive aggressive irony can be satisfactory... And you can just keep doing it until you get bored or run out of ideas.