yet another jQIR.

jquery.replaceimage.js

(function($) {
	var options = {
		path: '/img'
	};

	$.replaceImageSetup = function(o) {
		options = o;
	};

	$.fn.replaceImage = function(ext) {
		return this.each(function() {
			if (!this.id) return;
			var self = $(this);

			var img = $('<img/>');
			var src = options.path+'/'+this.id+'.'+ext;
			img.attr({
				src: src,
				alt: self.text()
			});
			var a = $('a', self);
			var element = a.length ? a.eq(0).html(img) : img;
			self.html(element);
		});
	};
})(jQuery);