Cellular News reports that O2 UK has announced it will offer free text message updates for the Twitter service from next month. From the start of August, every O2 customer will be able to switch on text notifications within Twitter and receive replies and direct messages free of charge. O2 customers will also be able to send updates to Twitter as part of their normal text message bundle or for the cost of a normal text. The move is similar to an earlier offering from rival Vodafone.