Google Sites has again been updated to give more new features:

• Auto Navigation
  

  You can now make the sidebar navigation gadget show every page in a hierarchy view automatically, listed alphabetically.  Use the Edit Sidebar link and then Edit link in the Navigation box: then tick the Automatically organise my navigation box.

• Subpage Listing Gadget

  You can now add a gadget that adds a list of the subpages in the same expandable/collapsible format as the site sidebar navigation gadget.  This is updated automatically with all of the subpages and you can even use it as a navigation gadget for the top level.

  Insert > Subpage listing

• 

  Page Layouts

  Rather than the two previous page layouts (one and two column) there are now seven (yes 7) page layouts, some of which include a side bar of their own.  This means you can disable the site sidebar and have a different side bar on every page (but it's fixed at 150pixels, where as you  can set the site sidebar to any width).

  Edit Page > Layout

• 25 New Themes

  Google have provided 25 new themes very similar to the Google Page Creator themes, so migrated sites should look as similar as possible.

  More Actions > Manage Site > Themes

• Attachment Handling

  You can now see the attachments on the whole of your site in one place: More Actions > Manage Site > Attachments.  This new tool also allows you to upload attachments to the Top Level of your site (e.g. http://www.example.com/picture.png).

• Deleted Site URL (web address) Re-Use

  You can now re-use your deleted site URL.