The Google Sandbox - what it was on day one, i.e. New Sites = Poor Results in Google, from when it was coined the Sandbox Effect to when Matt Cutts confirmed the Sandbox after much debate over the Sandbox, if it existed or not. In any event, most experienced SEMs understand the goal behind the "sandbox" and how it is more about the "trust" of a site (yes a site, not necessarily a specific page, imo) then about how old the site is.
Trust trust trust.
In any even, Andy Hagans has an excellent write up on how to earn more trust for your site. Heck, he named the article Secrets to Beating the Sandbox 2.0 REVEALED: The Ultimate Guide. That name, itself, is a link baiting art - a method of earning more trust, at this point in time. This article is worth a read.