This is going to be tricky. Is the Tour Sprint or Verizon? If it is Sprint, probably won't work, since it is now through Verizon. If it is a Verizon phone, might not work, especially if they are on an Alltel plan. They might need an Alltel branded phone for this to work.
Unlocking it did nothing, as Alltel is CDMA, and unlocking has to do with the GSM part.
He might be able to get around this. Seeing as he is your "friend" I'm sure he won't have to worry about you not giving him a refund if it doesn't.
I was a Verizon Tech department till Nov. last year... So this technically should work, if you have a tech or two who know what the **** they're doing... Which I can assure you, there are a LOT that do not...
If has access to his Alltel account online and has the ability to change phones there/ESNs it should work. But he'll have to call tech/sales and have the data plan put on his account. If the website doesn't do it for him.
I know with VZW when you activate a Blackberry or ANY smartphone, you CANNOT activate it w/o data plan.
Or he could just migrate his Alltel plan to a VZW plan.