Remember the days when sending messages and jotting down notes involved actually writing them down using pen and paper?

Well, now you can relive those pre-smartphone days with this accessory called 'Jackpen'. Invented by Andrew Jewson, this miniature ballpoint pen is designed to fit neatly inside the headphone socket of your mobile. The pen can also be pulled out and reinserted with the non-writing end to prevent ink from staining your pants. Retails online for £3.99 per pack of three.