Corporate partnerships, like marriages, can have their rough patches.

Witness Motorola CEO Ed Zander's comments a few weeks after his company teamed up with Apple to launch the Rokr (search), the company's new iTunes-equipped phone.

Apple CEO Steve Jobs had used the occasion of the Rokr launch to unveil the iPod nano (search), which drew raves, while reaction to the Rokr has been lukewarm.

"Screw the nano," a frustrated Zander said at an industry conference after repeated questions from the audience about Apple's tiny iPod.

Zander later claimed the comment was taken out of context, but the episode highlight the perils that come when companies with differing agendas join forces.

The last several months have seen a glut of corporate partnerships in the technology industry, with varying results.

"We're seeing a partnership feeding frenzy," said tech analyst Rob Enderle.

At the heart of unions is the idea that companies are learning that it can be good to stop competing in areas that are not their core competency in order to be more dominant in areas that are their core competency, according to John Barker, president of DZP Marketing Communications.

A perfect example is the Microsoft-Palm deal to equip the forthcoming Treo 700W (search) with Microsoft Windows Mobile (search) operating system, according to Barker.

Microsoft brought its industry-leading mobile OS to the table, while Palm brought its industry leading line of handhelds. Combined, the new product amounts to a "category killer," Barker said.

And then there are some tech partnerships that seem executed more for publicity reasons than anything else.

For example, when Google recently announced that its was teaming up with Sun to "make it easier" for users to freely obtain Sun's JavaRuntime Environment (search), the Google Toolbar and the OpenOffice.org office productivity suite, the news was greeted like the Second Coming.

Surely this was the partnership that would take down Microsoft!

Once the hysteria subsided, however, many observers noted that the only substantive thing agreed to by the companies was to allow users to download the Google Toolbar from Sun's Web site.

As one industry watcher eloquently put it, "Sun-Google: Where's the Beef?"