As of now, I do not use a lookup service. I have set up CID Superfecta (from PBX in a Flash), which queries several free sources, but the free resources are certainly not the most comprehensive. Vitelity charges 0.9c per lookup to their subscribers for calls coming in to one of the DIDs--afaik, they do not offer a standalone lookup service. cnam.info chargers 5 cents or 1.8 cents, depending on the database used for standalone service. Since they require a $25 startup deposit, I never went with them. Also, 2-5 cents just to have a call ring in is pretty pricey, IMO.