How to disable Google personalized search

Spotted on Google Blogoscoped (via Lifehacker): instructions on how to disable Google's "personalized search" function:

Google describes this (old) feature as “an improvement to Google search that orders your search results based on what you’ve searched for in the past,” going on to say that you “may not notice much difference at first, but as you build up your search history, your personalized search results will continue to improve.”

Not everyone wants Google to collect and store this personal data, though, so here's how to turn that off: Link.