UK iPhone carrier O2’s move to temporarily lower the 8GB iPhone’s price by £100 has boosted sales, according to a Mobile Today report. O2 stores in Newcastle, Birmingham, and London said they sold out of the 8GB model on the day the price cuts; the stores are expecting more iPhones to be delivered this weekend. An employee at Carphone Warehouse’s flagship Oxford Street store said sales had doubled, from 30 to 60 iPhones per day,…