I remember the templates at Logan, CLE, LGA, IAH, and others. The rule of thumb has been if United has influence at the concourse, you'll find the templates.

At Logan, there was a serious delay at security as a couple of passengers argued that their airline told them to carry their oversized bags to the gate to be gate checked. Since security would not let them through and was holding up the line, a long line of fliers developed. Finally, a security manager arrived and confirmed that, yes, the airline in question did not participate in the template program and to let the guys through.

Thankfully, you will not find the templates at STL concourse B, C, D, or E (my main airport). I don't know about concourse A.

When this template thing occurred, I went out and purchased new luggage to meet the requirements. This is not because of STL, but due to my return flights from "template" cities began causing problems.

You'll find a United thread that provides additional information at:

http://www.flyertalk.com/forum/Forum50/HTML/000395.html