(MONEY Magazine) – With long-distance phone rates as low as 5[cents] a minute--leaving them little more room to drop--the next move in the residential phone wars is likely to be drawn from the cellular playbook: bundled blocks of talk time for a set monthly fee.

Several such plans, some of which include both local and long-distance calls, are already being tested by the major long-distance companies. AT&T, for example, is quietly marketing bundled minutes to customers who have defected to the competition: In January, some high-volume callers were offered 500 minutes of long-distance for $24.95--or roughly 5[cents] a minute--with additional minutes for 7[cents]. Meanwhile, MCI WorldCom will start offering bundled plans in New York State this spring. Also in January, Sprint went a step further, signing up 500 Californians for unlimited long-distance service for $65 a month.

The question, of course, is whether these new plans save you money. As with similarly structured cellular deals, that depends on whether you'll consistently use all the minutes in your monthly block. Sure, the AT&T plan comes out to about 5[cents] a minute if you use all 8 1/3 hours worth of long-distance talk time. But the rate effectively jumps to more than 10[cents] a minute if you talk for only four hours in a given month--and to 20[cents] if you talk for only two hours. In the end, light to medium users will still generally be better off taking advantage of low per-minute rates. But if bundled plans are the future of long-distance pricing, heavy users could see significant savings down the road.

--ROB TURNER