This page lists links to a few other ratings sites I am aware of. Many use similar methods to what I show here.

Albyn Jones Soccer Ratings
The first site I found using methods similar in concept to what I show here. This site is no longer active.

Jeff's Sagarin's Computer Ratings
Jeff Sagarin's Ratings, published as a part of USA Today. Rates basketball, volleyball, golf, football, hockey, soccer, and baseball.

Massey Ratings
Ken Massey's extremely comprehensive ratings site. These ratings have bene adopted by HighSchoolSports.Net

MaxPreps - High School Sports
This site is what New Mexico soccer is officially using for reporting and rating high school sports starting in 2012.

Rivals.com -- for NM High School Sports
This site only tracks football, basketball, baseball, and wrestling.

CollegeRPI.com (No longer active)
Not a power ranking site, but this is the site that implements the "Rating Percentage Index" -- a strength of schedule rating system owned, operated, written and edited by Jerry P. Palm. We display RPI scores for teams on the team schedule pages. It now forwards you to --

CBSSports.com
Not a power ranking site, but a blog run by Jerry Palm, who originally developed the RPI site.

I have not made a study of how the rankings I show here compare to these other sites. In general, I think the methods most use are similar, some quite similar, some better, some not. But I do know for sure how I am doing the ratings shown here, and I am never quite sure how the others are done.