Despite the August launch timescale quoted when this news was announced, O2 has turned on text notifications for Twitter early, making the service live now, as the operator says "we’ve got everything ready early".

For those keen to get going with the alerts, here's O2's instructions: "To set Twitter texts up, head to Twitter, choose Settings then Devices. Once you’ve followed the prompts there, you can then choose which followers you want to get texts from. You’ll then receive each of their status updates by text message - you can also choose to receive every direct message you get too".

In addition, O2 customers can now also send Twitter updates to 86444 with texts to this number costing the normal text message rate or become part of inclusive bundle allowances.

O2 says it has a fair use policy for the free alerts - people who receive more than 600 messages per month will be asked to "moderate" their usage.