What you will need:

• PDFCreator – PDFCreator is a free, open-source application that can create PDF files from any file that you can print.  It fools your system into thinking that there is printer called PDFCreator.  When documents (Word files, web pages, photos, etc) are printed to this "printer", they don’t emerge on paper but are saved to a PDF file.  Since it is free, you can install it on all of your computers without paying a single penny.

The Green Tip:

Upon completing an online purchase, you’ll usually be presented with a receipt for your purchase.  Many would print this receipt out to have onhand in case they need it, but this can waste paper.  Instead, I print the receipt to PDF.  To make it easier to find, I put all of my receipts in a folder (appropriately called "Receipts") and name the PDF files in a way that I’ll remember what they were for.  e.g. "2008-12-23 – Amazon.com – Another Good Book.pdf"  Then, if I ever need to find my receipt, I simply open the cooresponding PDF file.  I haven’t yet needed to print a receipt out, but if I need to, they’ll all be there as good as new while a receipt printed at the time of sale can fade, tear, or get lost.  I don’t know offhand how many trees I’ve saved by not printing out my receipts, but every little bit counts.