With Java Script you can add an image to your blog that sits directly over any part of the page. Especially if there is an ad there, a picture looks much nicer. To do this you make a div object which contains the image you want to use. For this, you need to add this code to the HTML (Quellecode anzeigen):

<div id = "blume" style="position: absolute; top:150px; left:500px; z-index:10; width:80px; height:80px; background-color:transparent"><img src="http://www.path.to.your.image.file/hibbertiatrans.gif" id="pici" alt=""></div>
<SCRIPT LANGUAGE="JavaScript" TYPE="text/javascript" src="http://www.path.to.your.scripts/scripts/div3.js">
</SCRIPT>
In the body of the text, under the div object, is where you have to place the Java Script to make the image do something. This script makes the image move back and forth. The "top" and "left" values control the position of the image. Make a second div if you like with another id, such as "blum2", by copying and pasting the div tagged part.
You can find the source of my JavaScript  file here.
As long as the blog entry containing the div tag is on the page which is opened, the image will be there. Once the entry moves off the bottom of the page, you will have to enter it again near the top of your blog entries. Nothing actually needs to appear on the page in writing, just the div object.
Have fun and let me know if you have any problems.