Social Media Extravaganza

For Grantland:

• Facebook
• Twitter
• RSS Feed (this is maybe a stretch for social media, but worth a shot, right?)
• last.fm page for podcasts
  
  This is all I could find for Grantland. Either I'm seriously missing something, or they haven't established a huge social media presence quite yet, which would be understandable considering the site's relatively recent launch.
  

For Slate:

• Facebook
• Interestingly, Slate has multiple Facebook pages for its various sections and columns: Culture, Slate V, Double X, Slate Politics, Slate's Culture Gabfest, Slate's Political Gabfest, Digital Manners.
• Twitter - like on facebook, Slate maintains multiple Twitter accounts and lists the Twitter profiles of many of its authors. Some of them include SlateArticles, SlateForeign, TheBigMoney, DoubleXMag, ForeignPolicy Magazine, Music Critic Jody Rosen, and so on and so forth. They even list their copy editors' Twitter accounts. See the complete listing here.
• Apparently Google+ doesn't have business/corporate accounts yet, so for now Slate recommends following one of its authors and "unofficial Google+ ambassador" Farhad Manjoo. Slate also lists the Google+ accounts for some of its other writers here.
• Slate has a YouTube account in addition to their own video site at slatev.com
• Slate also maintains a page on last.fm, where it posts podcasts.
  
  I wonder if it's important for large publication like Slate to maintain many social media feeds so that their readers are more easily able to get updates on the topics they'd like to read, without getting buried in the stuff they're not interested in.