When I talked to Cingular in Dallas,Texas USA they told me they could give me a Cingular sim to replace my ATT sim if my Nokia 6620 was unlocked. But they said I would only be able to use as a telephone and not be able to download ring tones and not able to access the internet. Is this true?

Is there any technical diffence in the Nokia 6620 that ATT sold vs. the 6620 that Cingular sells other than that they are locked to their respective sims?

See More: Unlocked ATT Nokia 6620 limitations on Cingular