The Washington National Cathedral has created a prayer generator. The program asks for your name and religion (the options are Christian, Muslim, Jewish, or Other), and asks you to pick which issues are most important to you from a few short lists.
You can also enter your email address “if you’d like to receive a beautiful, printable copy of your prayer by email,” along with other “inspirational materials.”
Then the program generates a personal prayer.
The primary difference between prayers for members of different religion seems to be whether or not there is a reference to Jesus Christ; most of the sections of the prayers seem to be from the Book of Common Prayer, regardless of which religion was selected on the generator.
The website is attractive and easy to use, but its purpose seems somewhat oblique.