In my quest to use all of the equipment I already have at home to workout, I've created this fitness video with heaps of exercise ideas for you using a Medicine Ball. The one I am using is 4 kg. You can also use any non-weighted ball around a size 5-7, but with this you may have to increase the volume of some of the movements or they may be too easy.
I have separated the exercises into 4 regions; lower, core and upper body then finished with a final segment dedicated to getting the heart pumping!
Again with just one piece of equipment and a small amount of space you can still achieve a full body workout. Here is a link to eBay for medicine balls like mine at £16.90. They also have a choice of 2, 3, 4 or 5kg balls. There are lots out there this is just one example.