This isn't true; if you exercise - and don't sell - your options, you will be subject to the AMT. (Alternative Minimum Tax). During the original Internet bubble (and bust) this caused significant hardship for many people. Tip - don't take tax planning advice from random blogs.
Yes, this happened to a friend of mine. The stock options financially ruined him.
Go see a real CPA tax accountant. Don't wing this stuff, don't rely on advice from the internet.
In a dotcom bubble scenario this can make the difference between owing millions of dollars of taxes despite having never seen a dime and owing your standard income tax on actual profits.
Feel free to edit your post so as not to send people to the poor house.