Just like the company's FaceTime video calling service, which was introduced to the Mac shortly after its debut on iOS devices, Apple's upcoming iMessage service could also be coming to a computer near you.

The messaging service, which is seen as a rival to RIM's BlackBerry Messenger, will be first introduced with the release of iOS 5 this fall, but it may not be exclusive to iOS devices. According to references in OS X Lion's iChat framework, Apple could be about to build iMessage into your iChat application.

One of the things that distinguishes iMessage from plain old SMS messaging is delivery and read receipts. While both services use the same Messages app on your device, when you send a message to your friends via iMessage, you can see when it was received, when it was read, and even when your recipient is typing their reply — just like other instant messaging services. It's these delivery and read receipts that indicate iMessage could be coming to the Mac.

In the framework for the latest version of iChat under OS X Lion, one developer has spotted two new properties, highlighted in bold below:

@interface IMMessage : NSObject


IMHandle *_sender;

IMHandle *_subject;

NSAttributedString *_text;

NSString *_plainBody;

NSDate *_time;

NSDate *_timeDelivered;

NSDate *_timeRead;

Delivery and read receipts are features that were not previously built into iChat's native messaging protocols, and so these references are something new. Whether or not they point to iMessage integration on the Mac, or simply delivery and read receipts for iChat, remains to be seen, but I'm certainly keeping my fingers firmly crossed.

iMessage on your Mac would mean that not only could you communicate with your friends for free between iPhones, iPod touches and iPads, but your Mac could also join the party.

I've been longing for a way to send messages from my Mac so that I don't have to keep picking up my iPhone while I'm working. Sure, I could use services like Skype or AIM but not everybody uses these. In contrast, nearly everyone I know uses an iPhone.

I can't think of one good reason why Apple wouldn't introduce iMessage to the Mac. Again, it did the same with FaceTime earlier this year.

Would you like to see iMessage on your Mac?

[via MacRumors]