Here's the latest in the love/hate relationship saga between mobile operators and over-the-top (OTT) service providers...

Orange (NYSE: FTE)'s Orange announced a partnership with Google (Nasdaq: GOOG) on Wednesday to deliver SMS-based services in Africa. Meanwhile, Vodafone Group plc (NYSE: VOD) launched its own Facebook phone for pay-as-you-go users. (See Orange, Google Team for SMS in Africa and Vodafone Launches Facebook Phone .)

Hang on, aren't Google and Facebook the arch enemies of mobile operators?

Well, these partnerships show that some folks at the operators must believe in the old saying, 'Keep your friends close and your enemies closer.'

The new Gmail SMS chat service will use Orange's SMS platform to make Google's services available to customers in Africa, where mobile access is more widespread than PC and Internet penetration. The service is already available in Senegal, Uganda and Kenya. In the next few months, the service will be launched in Cameroon, Côte d’Ivoire, Guinea Conakry and Niger. Orange will also launch a trial service in Egypt.

Ultimately, Orange plans to launch the service across its entire African footprint, which has a total customer base of about 60 million.

It makes sense for Google to want to partner with an operator like Orange in this region where its reach is not as strong, according to Stela Bokun, senior analyst at Pyramid Research . And Orange has a "huge footprint" in the Africa and Middle East region, she adds.

Meanwhile, Vodafone has put Facebook at the heart of its newest handset, the Vodafone 555 Blue, which comes complete with a Facebook button right on the keypad. The device runs on Vodafone's own operating system and does not include 3G or Wi-Fi support. For data, users will have to be content with GPRS and EDGE.

The new device will go on sale in August in several Vodafone markets and is expected to cost less than £60 ($100) on a pay-as-you-go tariff.

Why this matters
They are fierce rivals, but mobile operators and OTT players such as Facebook and Google do need each other. [Ed note: Does that make them "frenemies?"] And these partnerships show where there is some common ground. (See Operators Accept Support Act Role.)

Also, the Gmail SMS Chat service in Africa is only the beginning for the Orange and Google relationship, as the companies said they are exploring other ways to bring other Google services to all of Orange's customers.

For more
For more on the rivalry between mobile operators and OTT players, check out these stories:

— Michelle Donegan, European Editor, Light Reading Mobile