As Nick described in another post, if your portable printer fails, it can really screw up your plans for the day in this age of electronic tickets and such. Here is a solution that will help you avoid being up that creek without a paddle.
Go to www.primopdf.com, download the free version and install it. Now you have a "printer" that is accessible from any program on your computer that can print. Except this printer prints it to a PDF file. You can copy the file to a CD, a USB thumbdrive, flash card/stick (camera) or even email it. For example you could put it on a CD or USB thumbdrive and go to the campground office to print it out. Or to any office store, Kinko's/FedEx or UPS store.