Protect yourself from the rain as well as ninjas with a samurai sword handle umbrella. Actually these won't do much in the way of protecting you from ninjas, but at least you will look and feel like one carrying it.
Available In fullisized "Katana" and travel-sized "Tanto."
$20- $30 from ThinkGeek.
Check it out here: ThinkGeek
Edit: The umbrellas in the first picture with different hand styles are available on Amazon for ~$20 to $40. Check them out: Amazon