Even Bill Gates has, on numerous occasions, expressed admiration of the iPhone, although he forbids himself and his family from owning Apple products (those poor souls). Steve Ballmer uses Windows Mobile smartphones, but many of his employees secretly cherish their iPhones.

Windows Mobile 6.x has been eclipsed by the iPhone as the operating system/phone of popularity among North America consumers. Microsoft is launching Windows Phone 7 in an attempt to claw back some of the market share lost to Apple, but the damage may be irrevocable since the iPhone is not the only threat to contend with (to wit, the momentum gaining Google Android and the ever-strong RIM).

The Wall Street Journal reports that at the Seattle Microsoft campus, plenty of employees tout about their iPhones. Microsoft’s chief experience officer for the entertainment and devices division, J Allard (who was a co-creator of the Xbox) openly uses an iPhone. Eugene Lin, a software engineer, is an avid iPhone owner who has developed his own iPhone app called Peekaboo. This openness is rare for higher-up management, who tend to hide their iPhones, while Microsoft’s commoners are less secretive.

Almost “10,000 iPhone users were accessing the Microsoft employee email system last year,” representing 10% of Microsoft’s workforce worldwide. In contrast, almost zero Apple corporate workers use Windows Mobile phones. If Windows Phone 7 turns out to be good, then the situation should change, but right now, Mobile 6.5 is arguably the worst smartphone operating system out there. Microsoft has changed one of its service fee reimbursement policies last year and now covers charges only for phones being powered by Windows Mobile.

Do not let Ballmer catch sight of your iPhone if you work for him.