Just plug in your TXP install path and use the Bookmarklet Builder to make yourself a nice little bookmarklet for posting to your TXP. The code below will also take the current page’s title and selected text. There’s a lot more data you can use like putting the current page’s url in a custom field.

javascript:
var d=document,
w=window,
e=w.getSelection,
k=d.getSelection,
x=d.selection,
s=(e?e():(k)?k():(x?x.createRange().text:0)),
f='http://PathToYourTXPFolder/index.php',
l=d.location,
e=encodeURIComponent,
p='?bm=1&Section=SectionName&from_view=1&Category1=CategoryName&Title='+e(d.title)+'&Body='+e(s),
u=f+p;
a=function(){
  if(!w.open(u,'t','toolbar=0,resizable=0,status=1,width=800,height=800'))
    l.href=u;
}
;
if(/Firefox/.test(navigator.userAgent))
  setTimeout(a,0);
else
  a();
void(0)