Yeah, you can, it's like 20 bucks... but you have to buy it online and pay shipping, which sucks. I'm wondering if they'll reduce the price and/or put it in retail stores now though.
I don't understand why it's 20... you could get a new sensor and dongle for 30, I figured at LEAST 15... I know it's just $5, but up until now the only reason to get a sensor was to replace an old one... so honestly, it should probably even have been $10.