You can do two years ago: you just need to put the number of days ago you want to start and end at as parameters... so
<?php cg_wayback(733,726); ?>
will do all posts between 726 and 733 days ago (a one week slot two years ago).
I'll think about the 'this day in previous years' idea, might be a different plugin :).
Hey - how do you do the bars on your blog, with the date on the far right, dividing entries up by day? That's cool, I'd like to steal it.
Yes, it's 1.5 compatible. I don't know if it works with older versions, I only have 1.5 (new WordPress user, here). And see the above answer - you can use it for a shorter time ago if you prefer...
Good idea. I'll look into it. I see you have an 'on this day' thing on your blog - can you point me to the relevant plugin or code?