Saw an Emerson box advertised on tv the other night that will take one phone line & turn it into two phone lines so you don't tie up your phone or have to buy 2 lines. It sells for around $40 & I was wondering if it is any good? The Emerson can be found at www.greatbuyusa.com it's right at the top of the page. A neighbor thought it might be good for his kids line? Any ideas? Thanks.