For my purposes, Bing is different from Google in two important ways. One, Bing Maps provides the awesome Bird's Eye View. And two, Bing features the Social Sidebar. If you have yet to fiddle around with the Social Sidebar on Bing, consider this a primer.
Before you get started, you will need to be signed in to Facebook. Then, on Bing's search results page, you'll see a dark-gray sidebar along the right edge. Here, you will see a Facebook box where you can ask a question on Facebook related to your current Bing query, tag friends, and add links from your search results page. Just click on the paperclip icon next to a search result link to add it to the Facebook box.
Below the Facebook box, you'll see two groups of people: Friends Who Might Know and People Who Know. You can use the first group to tag up to five Facebook friends, who will be notified when you post your query to Facebook. (Bing suggests friends based on their likes, photos, and public profile information, but your friends who restrict public sharing on Facebook won't show up in the sidebar.) You can't tag anyone in the People Who Know section, but you can mouse over them to get a glimpse of their latest Twitter activity.
The latest update to the Social Sidebar gives you the power to tag any of your Facebook friends, instead of just the few that Bing suggests. Microsoft is rolling out a change that adds a line that reads "Choose friends to notify" at the bottom of the Facebook box. Click on it and start typing the name of a Facebook friend to notify that person of a question related to one of your Bing searches.
This change makes Bing's Social Sidebar much more, well, social. In many searches, I found that the Friends Who Might Know section was empty, which left me with no way to tag friends. Of course, I could always just head to Facebook and ask them there. If Bing wants to horn in on my social-network activity, however, then I need to be able to tag friends who I know have some knowledge of my current search topic, whether Bing knows they do or not.
Have you been using Bing's Social Sidebar? If so, have you found it helpful or a new avenue for interacting with your Facebook friends? Let me know in the comments below.