Hello Tcat,
Great plugin. One little problem I've found. If you you emded the images using the IMG tag, they sit right on top of each other (normally they have a 2px margin by defualt). You can
see an example of what I'm talking about here.
Ideally you could give the thumbnailed image a CSS class and that way we could just define it in our style sheet on our own, or even better, in the AdminCP!