Thank you so much! This is EXACTLY what I was looking for.
I used to have WP websites on one installation and then the blog on another. I decided to get everything under one install of WP but could not figure out how the heck to get the different layouts working.
Your plugin is the solution. I have a template for the main website and one for the blog now and your plugin lets me choose which to use.
I will be sending a donation your way shortly in expression of my thanks!