Well now, it appears that the latest iPhone operating system, iPhone OS 4.0 has a little thing going on with social networking site Facebook as an article over on engadget reports that iPhone OS 4.0 shows evidence on low-level Facebook event and contacts integration.

They say this could possible mean unified contacts and calendar applications from Apple when they get round to launching the iPhone OS 4.0 on the next generation iPhone later in the summer.

Apparently according to gunning for safety, Apple may have created a “separate type of contact” especially for Facebook, which they say perhaps will be “friends” rather than contacts on the iPhone. They also make mention of a generic “SocialKit internal framework,” which could open the way for further integration with the likes of Twitter.

The guys also say that all this sides up quite nicely with an article posted on apple insider the other week about a “linked Contacts” feature which could be associated with every entry in the new iPhone OS 4.0 Contacts application.