Here are some of this week’s essential news from the search engine and social web scene:

• What’s Hot on Wikipedia? Wikirank Will Tell You

  Wikirank allows you to search for topics and get a chart of how many views their Wikipedia pages have gotten. (Researchbuzz Mar 29 2009)

• Microsoft closing Encarta online encyclopedia

  Microsoft plans to close its Encarta online encyclopedia, which competes in an arena dominated by communally-crafted free Internet reference source Wikipedia. (Yahoo! Tech Mar 30 2009)

• Goodbye Ms.Dewey, we hardly knew ye.

  Ms. Dewey was a viral marketing campaign started by Microsoft in October 2006. (AltSearchEngines Mar 31 2009)

• Slideshare April Fool joke goes disastrously wrong

  There’s already a really big backlash against this prank on Twitter – people who are using the hashtag are looking stupid, which is making them angry. (Phil Bradley Apr 1 2009)

• Twitter’s recruiting efforts hint at its plans

  Twitter is looking for search experts (Computerworld Apr 1 2009)

• Google AdSense drops AdSense for video

  Google AdSense has decided to no longer offer their Google AdSense for video (not to be confused with video ads, where advertiser’s videos appear in an ad unit in lieu of a text or image ad). (JenSense mar 29 2009)

• Google Study Shows Use of XML Sitemaps Helps Index Fresh Content Quicker

  XML sitemaps are a way for web site owners to help the search engine index pages on their web sites, through the use of an xml Sitemap. (SEO by the Sea Mar 30 2009)

• Helping Google Build a Better Bookmarking Tool

  Delicious is currently my favorite bookmarking tool of choice (Michael Gray Mar 31 2009)

• New blogsearch algorithm ignores blogroll

  Google has launched a ranking change that reduces the number of results that are returned because of blogroll matches. (SearchCowboys Mar 31 2009)

• Google Ventures Launches with “We May Steal Your Idea” Caveat

  If you’re a start-up that’s making moves despite the recession, Google wants to hear from you. (Marketing Pilgrim Mar 31 2009)

• Live Search Testing Icons In Sponsored Search Ads

  The screenshot shows a Honda logo icon placed inside a Live Search sponsored search ad. (SE Land Apr 1 2009)

• Google’s April Fools 2009

  Google is joining with several hoaxes (Google Blogoscoped Apr 1 2009)

• April Fools’ Day 2009: Google CADIE & More From Search Industry

  A roundup of some of the April Fools hoaxes from the search industry, starting with Google. (SE Land Apr 1 2009)

• How to Promote Your Slide Show Online

  Along with videos, a slide show is another great way to build and bait for links. (SE Journal Apr 1 2009)

• Microsoft To Throw $100 Million At Their Search Market Share Problem

  Microsoft has had a tough time branding their search portal, they even mocked their own attempts yesterday, on calling their search portal “MSN Windows Live Search on kumo@microsoft.com.” (SE Land Apr 2 2009)

• Closure of Wikia Search for Now!

  Jimmy Wales announced a few days ago, the closure of Wikia Search due to the ongoing economic recession. (PageTraffic Apr 2 2009)

• Twitter Redesign Includes Search & Trends

  Twitter admits its recent test of the search box at the top of the interface was a flop, so instead, it’s going back to the drawing board. (MP Apr 2 2009)

• Google uncloaks once-secret server

  Google’s big surprise: each server has its own 12-volt battery to supply power if there’s a problem with the main source of electricity. (CNet Apr 1 2009)

• 61 Pre-SEO Campaign Questions You Need To Answer To

  Questions I need answered if I in-source my search marketing (SE Guide Apr 2 2009)

• Interview with Wikipedia Founder Jimmy Wales

  Today, it’s hard to imagine life without Wikipedia, which has blossomed into the 7th most popular website in the world (bigoak Apr 2 2009)

• The Best Niche Social Media News Sites Right Now

  The following 35 sites are broken down into 8 different categories and each site has an active community and can help you get exposure. (10e20 Apr 1 2009)

• Google Shows Local Results for Non-Local Queries

  You don’t even have to be signed into your Google account. (SE Watch Apr 2 2009)