Google shows alternative suggestions in sidebar

Google starts to show some alternative results in the sidebar for a particular search. Search for lifehacker returns some alternative suggestions to lifehacker like Engadget, Gizmodo, Slashdot etc., in the sidebar ( Highlighted in red box).

Below are the some interesting searches. A search for apple yields.. competitors like dell, Sony and more interesting is it also shows some suggestion like banana, blueberry etc.,and a search for Google  returns

I find that one use for this feature could be you can find some alternate solution to a question. For example if you are looking for a alternative solution to mediamonkey (a media organizing software ) just Google it.

For now I can able to see this feature only when I logged in to my Google account. Any body already seen and uses this feature ?