I'm sure the www.fixyourownprinter.com website is upsetting many printer manufacturers. Among other things it contains lots of tips on how to extend the life of your ink or toner cartridge past the manufacturers best guess as to when it should be exhausted. And that kind of website suits me just fine. <smile>
Given that the printer cartridges for my HP LJ2605dn run about $90 CAD each, last time I looked I see no reason to replace them too soon. Once the toner has a serious fading problem then I'll replace the cartridge. The forums on that website had step by step instructions on changing the internal settings on the printer and where to look on the toner cartridges to put some opaque tape.
Do *NOT* pay for any such instructions on Ebay. No, seriously. Search Ebay for "toner secret" or "toner out override"
I will add that I really like the HP LJ2605dn. It prints on both sides of the paper in colour. While I've only printed less than a thousand pages since I got it it's been flawless. Hmm, ok, I did remove the HP Toolbox software from executing as it was sucking up hundreds of megabytes of RAM but that's difference.
Thanks to Crystal Long, fellow Access MVP for mentioning this website from the Slate article titled "Take That, Stupid Printer! How to fight back against the lying, infuriating, evil ink-and-toner cabal."