Alltel phones are CDMA, not GSM. If Cellular One is a GSM carrier, then an Alltel phone will do you no good for Cellular One. You should have looked at a GSM phone from Cingular, T-Mobile, or another GSM carrier, and had it unlocked. Alltel phones use an ESN (Electronic serial number), which practically makes those phones locked to that carrier, and ESN's are only found on CDMA phones. They're also found on TDMA phones, but TDMA is being phased out and there are no new phones using TDMA.
My son had a Cellular One phone which is a Nokia 6101. It got ran over by a car and it wasn't insured! I have a LG5450 from Alltel, Can this phone be used under his Cellular One account. The sim card from the Nokia is fine. I don't have an Alltel account right now. What is the process?