From today, Yahoo is integrating Yahoo Messenger into Yahoo Mail. Google integrated its Google Talk service into GoogleMail last year.

Yahoo said the addition of IM capabilities means that its users will no longer have to switch between using email and IM, as the two are interoperable. Messages can be transformed from email to IM, and vice versa, depending on a recipient's online status.

Yahoo Mail users can now run the two programs in the same browser window. The service requires no software downloads. Users will need a Yahoo ID to use the service, which is not compatible with other IM services.

Each messaging window is kept as a conversation tab within the webmail interface, allowing users to switch between IM windows and email conversations.

At a Tech.co.uk briefing yesterday, Tim Nunn, Yahoo Mail product manager, said that embedding IM into Yahoo Mail makes it "an even more social experience". He went on to explain that Yahoo is looking to bridge the gap between email users and IM users.

Over the coming three months, Yahoo will roll out the IM integration to its 240 million Yahoo Mail users.

In addition to Google's GoogleMail IM capabilities, Microsoft's Hotmail/Live Mail alerts users when email contacts are also on MSN Messenger. It allows users to choose whether to send an email or IM message to their contacts.