Most coupon sites allow you to print two copies of each coupon per computer, so if you have more than one computer then you are in luck!
Being computer geeks, we have many computers in our house. In addition to our current computers, we also have two computers that we replaced because they were too old and too slow. (One is my old laptop where if you move it at all the entire screen turns bright pink). We set up both as dedicated "coupon computers" and fire them up for the great coupons!
Don't think you can trick them by using multiple accounts on one computer. It doesn't work. We've tried. However, we have had some limited success using virtual machines on our apple computer.
Workplace computers are generally not an option as you need to install "coupon printer" software in order to print the coupons. You can only do this if you have administrative rights to install software on the machine.
Another option is to ask people to print coupons for you. Since obtaining multiple copies of coupons is key to successful couponing, find some way to get them!