Recently, I saw a commercial advertising services to soldiers. The ad targeted those who were deploying to Iraq or Afghanistan. The main message of the commercial was that soldiers should protect their family by purchasing a will and power of attorney packet from the company. After the sales pitch, a woman representing herself as a widow stated "I am so happy my husband thought of me and our children before he left." The advertisement did not state how much you would have to pay for the packet, but I'm sure it was not free.
If you are considering using this service or some other prepay forms service, you should know that your local Staff Judge Advocate Office will provide wills and powers of attorney for free. Unless you have a substantial estate or you are trying to do a complicated trust, the attorneys at your local installation will be happy to help you complete a will or give a general or special power of attorney to a family member.