After doing a Google search I came up with this after searching the first page of google results...it came from the Bright trading web site. BULLETS Married puts or "bullets" are simply contracts entered into between a trader, his firm, and another entity. Stock is purchased with an equivalent number of puts. The puts are exercised at the end of the trading day, leaving the trading account "flat." During the day, the trader can trade with the long stock, and can sell it without marking the sale short. This practice varies from firm to firm, and is generally only available to proprietary traders (due to margin rules and so on).
I'm writing naked puts with 20-40 days left, and letting them expire. As you know from options theory, this is exactly equivalent to selling covered calls. However the commissions are lower and the margin requirement is smaller.
Here's a screenshot of the performance report of my "GOOG daytrading system". Its based on IB's commission rates and 1000 shares per trade. <img src="http://www.elitetrader.com/vb/attachment.php?s=&postid=795398">