Updated

Microsoft Corp. employees are passionate users of the latest tech toys. But there is one gadget love that many at the company dare not name: the iPhone, The Wall Street Journal reported Saturday.

The iPhone is made, of course, by Microsoft's longtime rival, Apple Inc. The device's success is a nagging reminder for Microsoft executives of how the company's own efforts to compete in the mobile business have fallen short in recent years. What is especially painful is that many of Microsoft's own employees are nuts for the device.

The perils of being an iPhone user at Microsoft were on display last September. At an all-company meeting in a Seattle sports stadium, one hapless employee used his iPhone to snap photos of Microsoft Chief Executive Steve Ballmer. Ballmer snatched the iPhone out of the employee's hands, placed it on the ground and pretended to stomp on it in front of thousands of Microsoft workers, according to people present. Ballmer uses phones from different manufacturers that run on Microsoft's mobile phone software.

A Microsoft spokeswoman declined to comment and declined to make executives available for this story.

Apple CEO Steve Jobs referred an e-mail asking about iPhone use at Microsoft to a spokeswoman, who declined to comment.

Despite Ballmer's theatrics, iPhone users are in plain sight at Microsoft. At the sprawling campus in a Seattle suburb, workers peck away on their iPhone touch-screens in conference rooms, cafeterias and lobbies. Among the top Microsoft executives who use the iPhone is J Allard, who helped create the Xbox game console and is chief experience officer for the entertainment and devices division.

Nearly 10,000 iPhone users were accessing the Microsoft employee email system last year, say two people who heard the estimates from senior Microsoft executives. That figure equals about 10 percent of the company's global work force.

Employees at Apple, in contrast, appear to be more devoted to the company's own mobile phone. Several people who work at the company or deal regularly with employees there say they can't recall seeing Apple workers with mobile phones other than the iPhone in recent memory.

IPhone usage at Microsoft is the latest twist in the rivalry between Apple and Microsoft, tech-industry titans that have mixed it up in everything from computer operating systems to digital music players.

For many top Microsoft executives, seeing so many iPhones around the office is a bit like how a Coca-Cola Co. manager might feel seeing underlings drink Pepsi-especially since Microsoft makes its own operating system, Windows Phone, that powers handsets.

Employee iPhone use has led to some spirited discussions among Microsoft executives. At a retreat last March for dozens of senior Microsoft executives at its corporate campus, someone asked about employee use of iPhones in a question-and-answer period.

According to several people present, Andy Lees, a Microsoft senior vice president who oversees development of the mobile-phone software business, and his boss, Robbie Bach, explained that Microsoft workers often use rival products to better understand the competition.

Kevin Turner, chief operating officer, scoffed at that explanation, these people said. Turner said he discouraged Microsoft's sales force from using the iPhone, they added. "What's good for the field is good for Redmond," Turner said, recalls one of the people who heard his comments.

Ballmer took a similar stance at the meeting.

He told executives that he grew up in Detroit, where his father worked for Ford Motor Co., and that his family always drove Fords, according to several people at the meeting.

In what some employees interpreted as a sign that Microsoft was clamping down on the iPhone, the company in early 2009 modified its corporate cellphone policy to only reimburse service fees for employees using phones that run on Windows Phone software.

Microsoft has said it made the change as part of a broader cost-cutting plan.

Click here to read the full report.