I finally found it. Might not be the best solution, but it seems to work.
Line 161 of /wp-admin/post.php…
Before:
$location = 'post.php?posted=true';
After:
$location = '/';
This will take you back to the main page after a publish or an edit (save).
To do the same thing after a post delete, edit line 466 in /wp-admin/post.php…
Before:
if (strstr($sendback, 'post.php')) $sendback = get_settings('siteurl') .'/wp-admin/post.php';
After:
if (strstr($sendback, 'post.php')) $sendback = get_settings('siteurl') .'/';
If anyone knows a better/cleaner way of doing this, please let me know!
I am using WP v1.5.2 if it makes a difference.