if you dont want to add the <highslide></highslide> tag on each image when posting, just add these lines on the JavaScript Settings, on the wp-highslide options:
Add under the 'hs.preloadImages();' method, inside the 'window.onload = function() {' function:
var elements = $A(document.getElementsByTagName('a'));
elements.each
(
function(element)
{
if(element.href.endsWith('jpg') || element.href.endsWith('png') || element.href.endsWith('gif'))
{
element.className = 'highslide';
Event.observe
(
element,
'click',
function(event)
{
Event.stop(event);
var element = Event.element(event);
return hs.expand(this);
}
);
}
}
)
You need prototype loaded for this to work, so be sure to load it before (you can add the js link on the top of the wp-highslide settings).
With this script all image links on your blog will use the highslide thumbnail viewer.
I posted a portuguese tutorial here.