As experts decry the end of email and mobile operators look for the next SMS-style hit, Web-based micro-blogging and messaging services could be ready for their moment in prime-time.

Today AOL acquired Web identity manager and “lifestreaming” app SocialThing, which itself was somewhat a knock-off of more well-known activity feed application FriendFeed. SocialThing, which is still in beta and had raised just a handful ($300,000) in funding, let users keep up with what their friends are doing – as well as broadcast their own status updates -- on a variety of online sites such as Twitter, Flickr and YouTube.

Such “news feeds” have become an increasingly popular way for Web users to interact online, both as a feature of larger sites such as Facebook and in standalone form at sites like SocialThing, FriendFeed and micro-blogging service Twitter. Other key, though smaller, players include Tumblr, Jaiku and Plurk. Also notable is that most of these services have mobile client components; several mobile-only social network and lifestreaming apps have also emerged, such as Loopt, Limbo and Whrrl, which also add location-based capabilities to the mix.

What makes such services notable for service providers is that even if they are not able to survive as standalone businesses, the concepts of news feeds and lifestreaming are likely to compete with – as well as complement – existing messaging services such as email, instant messaging and SMS. They also dovetail extremely well with concepts such as identity, directory services and location – capabilities that carriers are capable of providing via their networks. Just this week, ABI Research forecasted that location-based social network services could generate $3.3 billion in revenue by 2013.

Even more signs of life and health: Secondary applications and markets have emerged around the market leaders, including social feed search (such as Summize, recently acquired by Twitter), news feed infrastructure services syndication (such as Gnip) and even an open-source, federated competitor to Twitter (in the form of oddly named identi.ca). (For more on such next-generation messaging sites, and what they mean for carriers, read: Chasing SMS).