In the recent months, the real time search engine market has been firing-up. There are many services around trying to gain some market share in this newly found area. We did some research, read many articles, and covered up most of what’s out there (if we missed any service, please let us know in the comments).

We followed a simple criteria to pick services and build our list: Any service must be (1) Real-time and (2) NOT limited to Twitter search results. Here we go:

The did-not-make-it-list. This includes the services removed from the main list above, because they are not real time or restricted to Twitter only:

Topsy: Although this provides some good insights about the active Twitterers in relation to a certain story, it is limited to Twitter. In my opinion, it can be useful to find not only conversations and links, but people, too. SearchMerge: It’s search capabilities indexes FriendFeed, Last.FM, Google, Flickr, Twitter, YouTube and other services. But not in real-time. We like the product, but it didn’t make our list! Twitter Search: Obviously it didn’t make our list because it’s limited to tweets, but it’s the fastest way to search Twitter! TweetMeme: Again a great and real-time service, but limited to Twitter. The bunch of smart people behind it figured that there are many similar Twitter search services around, so to be noticed they created a trendy ‘ReTweet’ button – the same as the one at the top of this post! Realtime@Google@Omgili: It is a 2 day old service which integrates Web page indexing with real-time Twitter results and re-tweet ranking. Again, it’s a great start for Omgili to take a chunk of the real time search market, but it’s still limited to Twitter.

While there are a lot of similarities in the services provided by the above real-time search engines, there are also some unique differences that make each one of them unique in a way or another. Which one is your favorite? Do you think real-time search is valuable or maybe over-rated? Please use the comments section below to let us know your thoughts.