I think Proporta have just been trying to confuse us. First they bring out the Keychain GPS 2000, reviewed here by Andrew Merritt, and then they bring out the Keychain GPS SiRF III Receiver, reviewed here by Andy Langdon, which is even smaller! Read both reviews to get a flavour for the sweet spot between size, battery life and notification LEDs. Or just flip a coin, to see which one to buy...?