How do you make a cheap, easy cage for guinea pigs?

Simple solution is to allow them to play in kiddies pools at least once a day and to also bring them outside, with supervision of course to let them explore and feel a little more free. BUT always make sure that the grass whereever you live is not treated with any types of chemicals, this could be harmful to them. They just need a little space to run around for about an hour or so. and five guinea pigs! bless you. I had two and they were a handful! And just being the guinea pig lover that I am... don't forget to give them vitamin C each day, whether it be in drop form in thier water or little pieces of oranges. hope this helps.