I have to admit this made me laugh: I’ve just come across this pedal-powered tennis ball machine made out of recycled (spot the pun?) bike parts – looks really nifty, not to mention eco-friendly. Just make sure you’ve got a really fit buddy to power the sucker while you’re hammering away at your backhand!
This gives new meaning to the phrase portable tennis ball machine – after all, a lot of the weight and expense of most machines is the humungous battery that comes with it! This definitely gets an A+ for innovation; I’m just not so sure about the usability aspects. Nice work, guys!