You can replace any standard door knob with one of these sets.
Brad's Deals Editor Michael,
This MiLocks Remote-Controlled Door Knob Set drops from $129.99 to $65 at Smarthome.com. Shipping starts at $10. However, even with the shipping fee added, this is still the best deal we could find for one of these sets by $47. These door locks come with two radio frequency key fobs and can be remotely locked or unlocked from up to 10' away. Two keys are also included. There is no sales tax (except CA).