Previous/Next Excerpt?

Hello,
I am running a simple photoalbum based on wordpress 1.5.2
I use the post excerpt field to link to the thumbnail and the post content to link to the actual sized image. I also use The “Next/Previous Post in same Category” plugin in order to implement a category based browsing of the posted images. The other thing is a plugin called “Random Excerpt” which I use to put random thumbnails on the main page of the site.

What I need here is a way to get the previous/next post excerpt and the previous/next post in category excerpt in order to put a thumbnails for the previous and the next image.

Any ideas ?

~Cheers~