This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Everyone who is certified recieves a certificate saying which test they took and when. An employer could request to see the certificate. Other than that, there is no master list that I've heard of. Nor do I think that Sun offers a service for employers to verify certification. But I may be mistaken.