Hey Mitchell,
Sure there is
Session Restore on Apple's Safari Extension's site.
My preference by far: Sessions
Try out my script (in the post below) to visualize your windows and tabs:
I've written several scripts over the years to save and restore Safari sessions, but these days I just use the Sessions extension.
I was playing with one not too long ago to write them to an HTML file, but I can't find it right now.
-Chris