I've installed the Hoverbox addin but got two problems with it (I'm using the horizon template and have renamed the appropriate css file)
1) The enlarged view is overlapped by other small thumbnails. So basically the enlargement is not broght fully to the foreground
2) The page links start to the right of my last thumbnail row and are then broken to the next row below all thumbnails
I've only tried this out on my local PC and have not made the changes yet to my actual photoblog on the web so I don't have an example to show. If neccessary I'll make a complete backup and change it online...