Here's an alternative link for the Expandable Post hack ( Summarized Post ). Instead of the "read more" link, you can use an image if you want to make it more visible. If you haven't implemented the Summarized post hack yet, you can apply it by following the instructions here. I prefer using an image cause it adds color to the overall design of your blog.
So here are the simple steps to follow on changing your "read more hyperlink" into an image.
1. First is to have your image or button as link for the summarized post. I recommend to make your button in Adobe Photoshop. I'll post ready to use "Read more..." buttons in the next update.
2. Go to edit HTML under layout tab.
3. Check the "expand widget templates" box
4. Search for the Read more line or the text you used as link for the summarized post
5. Replace it with this code: 
<img src='IMAGE/BUTTON URL'/>
7. Preview your template.
8. Save.
Blogger Hacks: Using an image as link for Expandable post hack
