Populating form contents from GET - especially radio buttons
I went ahead with the one-by-one re-populating from GET (on a timeline and all that!). The form doesn't need to be highly reusable and won't be modified very frequently after roll-out, so in this particular case, it was a matter of 'getr done' rather than 'getr done the best way'.

For the radio buttons, I ended up with a series of these:

&lt;span&gt;
  &lt;input id="partner_systemIntegration_1" name="partner_systemIntegration" class="element radio" type="radio" value="yes"  &lt;?php if(($_GET['partner_systemIntegration']) &amp;&amp; $_GET['partner_systemIntegration'] == "yes") { echo 'checked'; } ?&gt; /&gt;
  &lt;label class="choice" for="partner_systemIntegration_1"&gt;Yes&lt;/label&gt;
&lt;/span&gt;
&lt;span&gt;
  &lt;input id="partner_systemIntegration_2" name="partner_systemIntegration" class="element radio" type="radio" value="no"  &lt;?php if(($_GET['partner_systemIntegration']) &amp;&amp; $_GET['partner_systemIntegration'] == "no") { echo 'checked'; } ?&gt;  /&gt;
  &lt;label class="choice" for="partner_systemIntegration_2"&gt;No&lt;/label&gt;
&lt;/span&gt;


It's klunky, but when I tried to break it out into a function it failed. I'm using WordPress and a plugin that allowed PHP in the post/page content itself. When trying to define and use a function, I got some sort of eval error/warning, so I'm just doing it one at a time. Not the epitome of elegance and not my ideal choice, but now I can move on.