Presentations (e.g. Powerpoint) are often published on the web in PDF format. Unfortunately, a lot of Windows printer drivers (e.g. mine) will only permit one page per sheet which is a pain if it’s 60 pages but only 50 words a page. A little rummaging on the web turns up CutePDF Writer which includes the ability to print multiple pages per sheet. You select it like a printer and it prompts you for a filename where it sends the processed PDF.
I’ve already used it to save paper/ink and make presentations more perusable. I’ll use it future for any presentations I publish too. It’s free and claims to have no evil hidden extras.