Starting with this thread at WebmasterWorld by msgraph, on a particular Google patent there’s been some lively discussion on explanations of Google Sandbox, as well as specific efforts by Google to thwart common SEO practices to manipulate search results. It remains to be seen how much of it has been implemented by Google, but appears to make some interesting connections and also fuels new speculations.
Some interesting excerpts on linking:
 Consider the example of a document with an inception date of yesterday that is referenced by 10 back links. This document may be scored higher by search engine 125 than a document with an inception date of 10 years ago that is referenced by 100 back links because the rate of link growth for the former is relatively higher than the latter. While a spiky rate of growth in the number of back links may be a factor used by search engine 125 to score documents, it may also signal an attempt to spam search engine 125. Accordingly, in this situation, search engine 125 may actually lower the score of a document(s) to reduce the effect of spamming.
Takeaway: Don’t get too many links too fast.
 The dates that links appear can also be used to detect “spam,” where owners of documents or their colleagues create links to their own document for the purpose of boosting the score assigned by a search engine. A typical, “legitimate” document attracts back links slowly. A large spike in the quantity of back links may signal a topical phenomenon (e.g., the CDC web site may develop many links quickly after an outbreak, such as SARS), or signal attempts to spam a search engine (to obtain a higher ranking and, thus, better placement in search results) by exchanging links, purchasing links, or gaining links from documents without editorial discretion on making links. Examples of documents that give links without editorial discretion include guest books, referrer logs, and “free for all” pages that let anyone add a link to a document.
Takeaway: Forget about reciprocal linking and focus on a consistent and measured program of achieving content relevant links such as those that come from press release pickups and articles.
Here’s a summary of takeaways from WMW:
-Continue building links over time and consistently – do not stop.
-Don’t add links too fast.
-Get links from fresh pages (blogs, news sites, pages on sites that change often)
-Vary anchor text over time
-Don’t change the content of your key pages as not to reflect incoming anchor
-Domain name registration length of time, registrar and name servers may have an affect
-Add new pages of content to your site continuously and consistently over time
-Bookmarks to your site/pages is a very good thing
-Put Adsense on your site and make sure it gets good clickthrough
-Rank history and consistency affect current ranking
-Make your site sticky – engage visitors to stay on your site for longer periods of time and to return
Listing these suggestions does not necessarily mean they’re worth acting on, but interesting all the same.