OMG this worked and it is so simple!! Thanks!

Basically, I have one background image in the body set to repeat-x and positioned at the top. Then I went and put the following code into the HTML/CSS inserts:

html{background:#EEF2FB;background-image:url('http://www.myasha.org/images2/bg-bottom.jpg');background-repeat:repeat-x;background-position:left bottom;}

This adds another background image to the html tag and positions it at the bottom. Note that I had to put the background color in the html tag and remove it from the body tag.

Go check out the effect here:

http://myasha.org/tempasha/

Thanks again Ata for your awesome theme. (Now I need to pretty up that site. Those background images and colors, etc., are just placeholders. Not the ones I intended to use in the end.)