Toll Brothers Inc., a publicly traded luxury builder with 250 projects in 21 states, recently began a major push with its own version of the idea, offering maximum payment coverage up to $2,500 a month for six months over a two-year period. Toll's national marketing director, Kira McCarron, said that although removing the financial fears of potential buyers "is important, we see (the mortgage protection plan) as just one tool in the toolbox" needed to sell new houses in 2009.

From a consumer perspective, job-loss protection -- insurance coverage worth up to $15,000 (six months times $2,500 maximum) of monthly mortgage debt -- sounds like a no-brainer.

But there are some wrinkles and issues you need to know about upfront:

-- Though there's no direct cost to the buyer, that doesn't mean it hasn't been tacked on subtly somewhere in the deal -- possibly in the price from the seller or builder.

-- There are key exclusions and coverage limits. For instance, the Rainy Day program doesn't kick in for two months after closing. Self-employed persons, independent contractors and active military members are not eligible. There's a 30-day waiting period after you lose your job before the first insurance payment is made.

-- The Toll Brothers plan is only available to buyers who use the company's affiliated lender, TBI Mortgage Co. Consumers who know of a forthcoming layoff or "any impending job loss" are ineligible. The program excludes loss of income through voluntary resignations, "willful misconduct," and seasonal shutdowns.

Bottom line: Even when it's "free," read the fine print.