It's useful to be able to save a webpage as a PDF (e.g., to attach to a Help Desk request). Below are instructions on how to do this within the major modern browsers:
Google Chrome's built-in support for "printing" a page to a PDF file. Simply click the wrench in the top-right corner and choose Print > PDF > Save as PDF.
In Windows the print-preview window lets you adjust the page layout from portrait to landscape, select only certain pages, and access other options by clicking Advanced.
The Print dialog in the Macintosh versions of Chrome and Firefox (as well as every other Mac app) provides a PDF drop-down menu that lets you create a PDF of the page and fax or e-mail the PDF file, among other options. The Save As dialog lets you add a subject or keywords for the file. You can also require a password to open, copy, or print the PDF.
Firefox will list PDF options in the Print dialog on Windows PCs if the machine has PDF software installed.
If you don't have a copy of Adobe Acrobat you can download free software (e.g., CutePDF Writer) to be able to print as a PDF.
Internet Explorer (9 or greater)
Internet Explorer 9 and greater let you right-click a page and choose either "Convert to Adobe PDF" or "Append to existing PDF."