Preton Saver is a handy utility for anyone who uses Windows with an inkjet printer, especially if much of the stuff you print is not for long-term storage and doesn't need to look pristine.
It's a simple utility which helps you save ink, and can also keep a running count of how much ink (and money) you've saved. Best of all, you can get a free licence if you'll be using the program for non-commercial (ie, domestic) purposes.
To start, head to http://www.preton.com/free.asp. You'll need to supply an email address in order to get your free licence. By return, you'll get a licence code and the download link. Copy the licence code into your Windows clipboard. Once the software is installed, and you've pasted the licence code into it, you're ready to go.
Each time you print from a Windows application, the Preton Saver screen pops up. You can choose anything from a 0% to a 70% saving in ink, just by adjusting the slider. Then click the Print button and your print job proceeds as normal, albeit with less ink. Note to those who use screen readers, I have not tested the accessibility of the program's main screen.
If you're in the habit of printing out documents or emails so that you can read them in comfort, but you then quickly end up throwing them away, a program such as this is ideal. It'll certainly save you money, and works very unobtrusively. It runs under Windows XP and above, and is available in both 32 and 64 bit versions. The initial download is less than 1 MB, but it does seem to download an additional 6 MB of files during installation, presumably to ensure that you always have the latest version.