Yes, tennis racquets (and the odd tennis ball) as wallpaper. It shouldn't really work, but it does to great effect in three variations, two colours of the racquet design and one featuring the tennis ball too. The colours and the design lend themselves well to a retro too, especially for a feature wall.
All are digitally printed on superior quality, smooth matt print wallpaper, with each roll 10 metres long and 52cm wide. Certainly not cheap at £160 per roll (or £3 for a sample piece), but you'll be the talk of the tennis club if you opt for a roll or two of this for your home.