"Panels are great, but how do I change this one page?"

In a hurry to get this information up... Sorry for any typos :)

From the project page: "Provides a new Forms API element which is a select/radios/checkboxes element that has an 'other' option. When 'other' is selected a textfield appears for the user to provide a custom value."

This module lets you take the input from a field and allows using HTML and token replacement (or alternately PHP) for display.

"File entity provides interfaces for managing files. It also extends the core file entity, allowing files to be fieldable, grouped into types, viewed (using display modes) and formatted using field formatters. File entity integrates with a number of modules, exposing files to Views, Entity API, Token and more."

This is the module that is used on this site for code highlighting.

I can't believe that I haven't heard of this module until now. Maintained by Joachim Noreiko, a very prolific module author, this module lets you create views where the values can be edited inline.

Joachim's demo vid (~5 minutes) https://www.youtube.com/watch?v=g_D4z4Bw6iw

I just read a great article on this that breaks things down very well. You can find the original article here: http://fredparke.com/blog/create-your-own-tokens-drupal-7

Basically, you need to use two hooks. The first one tells the system about your token. The second one contains the specific logic for your token.

Works well with Geocoder. Used in Drupal Commerce. Quote from Mediacurrent: "Address Field - I used to use the Location module fairly often and in early Drupal 7 I used this module. I tend to like the Geofield module a lot more than these particular modules." http://www.mediacurrent.com/blog/top-drupal-7-modules-winter-2014-edition

There are contributed modules that will help with this that are listed below. You can also use Form API's #attributes to add in an HTML5 placeholder. Here's an example using Drupal Form API: