Alltel will activate it.
I have a sprint Diamond on alltel right now and it works 100%, flash alltel rom, edit epst, and install Alltel PRI and you will have everything working.
Alltel does not care if it is sprint, Verizon, US Cellular or any other carrier ESN. I have activated all of those carriers phones on Alltel and never with a problem.
So you will be safe. Its a cheap way to get phones to