A new partnership between Facebook and AOL will see the social networking site's Chat feature integrated with the latest version of AOL's AIM instant messaging platform.
The agreement will allow Facebook users to chat with friends when replying to AOL email contacts.
AOL said in a blog post that it will also add its Lifestream application to AIM, allowing users to receive updates from contacts on social networking sites, including Digg, MySpace, YouTube, Flickr and Twitter.
The announcements are another example of Facebook attempting to make its way into the email space, and AOL continuing to target the social networking space.
AOL owns the standalone Bebo social networking site, but it is nothing like as popular as Facebook and MySpace.
Google, meanwhile, announced yesterday that it intends to take on Facebook with a new product called Google Buzz.
Buzz uses Gmail contacts to build a social network, and interacts with YouTube, Flickr, Picasa, Blogger and Twitter to share media. A mobile version of Buzz will also use GPS to allow geo-tagging information to be shared.
The moves by all three companies add considerable weight to analyst firm Gartner's prediction that email and social networks will soon become one.
"The rigid distinction between email and social networks will erode. Email will take on many social attributes, such as contact brokering, while social networks will develop richer email capabilities," said Gartner analyst Matt Cain in a recent report.
Mickael Remond, chief executive of enterprise IM firm ProcessOne, argued that the announcement is yet another step towards "breaking down walls between online communities".
"With the integration with Facebook adding about 300 million potential users, XMPP is now by far the largest standard protocol for instant messaging and real-time web communications," he added.
"Gtalk, Nokia Ovi and Livejournal all have chat based on XMPP meaning that it now also has the largest instant messaging user base in the world. This is a demonstration of the growing popularity of XMPP in the messaging space."
Rather bizarrely, when contacted for further comment a Facebook spokeswoman said the firm "doesn't comment on speculation about future products".
Almost two years late - and just as AMD is readying 7nm Zen 2 for early 2019
Eye-wateringly expensive smart speakers take just six per cent market share, claims Strategy Analytics
TSB fraud hotline so over-run with complaints it takes hours to even speak to an operator
Sale of Toshiba Memory ready to go ahead after Chinese anti-monopoly probe concludes