Following the reveal of its Cr-48 notebook Tuesday, Google is now looking for Chrome OS testers as part of its pilot program. Each tester will receive a Cr-48 notebook from Google equipped with the Chrome OS and will be expected to provide detailed feedback to Google about the upcoming OS. But be warned, Google has said that the "Pilot program is not for the faint of heart," and reminded potential applicants that the Chrome OS is a "work in progress." Applicants must be at least 18 years old and live in the U.S. as Google currently cannot ship Chrome notebooks internationally "due to product certification requirements." Interested readers can sign up here under one of five categories named "business, education, non-profit, developer and individual." Just remember that applications close at 11:59:59 PM PST on December 21, 2010! Google will contact successful applicants after the closing date.