Small thumbnails for most read/commented and related posts

Hello,
I use the plug ins Most Read in XX Days, Related Posts by Category, WordPress Related Posts and WP-MostCommentedPosts, to bring up lists of posts in my side bars.

Does anyone know how I can generate and call smaller thumbnails (maybe 75px x 75px) to appear next to each link created by these plug ins.

I also use Thumbnail For Excerpts to automatically call the first image of a post and create a thumbnail (150px x 150px) for the loop.

I don’t use custom fields because of time constraints. I’ve spent the past two weeks trying to write something of my own and searching for a plug in.

Many thanks

Rich