This can only be done if you have the paid CSS upgrade. Although modifications you make with CSS you have to write yourself so it is not advised if you don't already know much about it. To see what it could look like you can preview CSS changes under the "Appearance" menu. Paste in the code below and select "Add this to <existing stylesheet>".
.post {position:relative;}<br />
.meta {position:absolute; bottom:1.5em; width:100%;}<br />
.meta .tags {float:right;}<br />
.post-footer {margin:10px 0 30px;}
It should work fine as long as all your tags fit on a single line. I'd imagine that this isn't the most important thing in the world so raincoaster's idea is probably the best but at least now you get to see what your blog could look like.
lh