Bill Slawski gives us a list of Twitter acquisitions. Some of them Twitter execs introduced to the community in a blog post, while others were introduced by news organizations like The New York Times. These companies are mostly small startups, with only a handful of people building innovative technologies.

Rebecca Lehmann wanted to better justify the time and the money spent on a variety of Google sites for clients, so she set out to find a way to determine the exact location of referral URLs. She runs through several possible methods, from redirecting landing pages to manual tagging, with pros and cons for each.

Josh McCoy quickly sums up the 2010 paid search year before moving on to 2011 and what to focus on for Google. He runs down a list of features Google has added, including elements to the data field "links to your site," and explains how best to use them. He also notes, "I have a good feeling that Bing is going to start gobbling up market share this year so it's in your best interest to spend some time in the Toolbox."

Ruud Hein suggests building what he calls an empathy site -- one that will allow SEO experts to experience what their clients go through. Though he doesn't explain this very well, he seems to mean creating sites to test your SEO skills and empathize further with clients -- one for a large market, and another for a niche market.

Resolutions have never worked for Kate Morris, so instead she gives us five SEO campaign tactics to explore in 2011. These includes areas such as HTML5 that "are either up and coming or becoming major cornerstones to every search marketing campaign," she writes. This year, test things and push boundaries in order to broaden your skills and hone your expertise.

Matt Cutts takes a look back at predictions he made two years ago but never published. Yes, he's throwing out predictions for 2009. Among them were that market share for IE would fall below 50% in some countries in Europe, and semantic Web technology wouldn't take off, at least not in generally accepted ways. See the hits and misses, according to Cutts.

Greg Jarboe writes about what makes a YouTube ad worth spreading after a similar question got asked by Chris Anderson, curator of TED. Jarboe analyzes several videos to make a point, pointing to the Old Spice YouTube ad viewed more than 26.6 million time, according to the Viral Video Chart. This was shared 396,060 times since it being uploaded on Feb. 4, 2010 with 381,089 Facebook shares, 10,746 tweets, and 4,225 blog posts.

Bill Slawski tells us about a patent application from Microsoft for a process called "Temporal Dynamics" that refers to the tracking of changes in documents. For example, it looks at changes to anchor text in a document, colors and sizes of images, tags assigned to documents, and positions of text or images. Slawski suggests this tool might be used to influence search results and rankings. He explains how.

Hollis Thomases explains why experts say, "the real sleeper tool in the online media planning world is attribution reporting." He details the players in the field, along with the challenges of reporting, and the process leading to success.

Jamie runs down the 10 best apps of 2010, according to SEOmoz. The list looks at the best combination of features, usability and price. In no particular order, the list mentions Google Analytics, KISSmetrics and MailChimp. Scroll down to the end of the post and you'll find a list of an additional 15 apps the SEOmoz team felt deserved a mention.