Encouraged by an immediately working backlink for the last post I added an experimental trackback form to the template of this blog, it allows manual trackback pings:
<!-- trackback form --><b:if cond='data:blog.pageType == "item"'>
<b:if cond='data:blog.title != ""'><!-- trackback blog_name -->
<b:if cond='data:blog.pageName != ""'> <!-- trackback title -->
<form action='#requires.javascript' id='track' method='get' name='track'
onsubmit='document.track.action=document.track.back.value;
document.track.method="post"' target='_blank'>
<input expr:value='data:blog.url' name='url' type='hidden'/>
<input expr:value='data:blog.title' name='blog_name' type='hidden'/>
<input expr:value='data:blog.pageName' name='title' type='hidden'/>
<input name='back' size='50' type='text' value='http://delorie.com:81/'/>
<input type='submit' value='ping'/></form>
</b:if></b:if></b:if><!-- end of trackback form -->
Apparently you can add this form to any type='HTML' widget after going to Layout: Edit HTML and checking Expand Widget Templates. I used #track:target { display: block; } in the CSS to show the form only when it's the target. Text mode browsers will see it anyway, but maybe they have no JavaScript.
