Use your NFC-equipped Android phone to unlock your KeePassDroid database.
Requires:
* A phone which can write to, and read from, NFC tags (such as the Nexus 4)
* KeePassDroid, also available in the Play store.
* An NFC tag -- search for "ntag 203" or "mifare ultralight" online. Shouldn't cost more than a few dollars.</br></br>