I wanted to share something with you guys that would make your cool little javascript more efficient and smoother using ajax technique.

If you add the following lines in your code for the
function oImage(imgDate, imgSrc, imgTitle, imgCat, imgTxt, imgSize) {
this.imgDoc = new Image();//add this line
this.imgDoc.src = imgSrc;//add this line
this.imgDate = imgDate;
this.imgSrc = imgSrc;
this.imgTitle = imgTitle;
this.imgCat = imgCat;
this.imgTxt = imgTxt;
this.imgSize = imgSize;
}
although it may look modifed I am sure you get the drift, this will render the images at the start of the load of the page and make the slideshow fluid and also make older browsers or computers without much ram to be able to still view the pictures without delay....

good luck, keep up the good work!