In the name of writing something useful for once, here's a magical wget incantation, useful on *nix boxen or Windows machines with a port of wget (e.g., via Heiko or Cygwin), for fetching the entirety of your blogspot blog to your local hard drive:
wget -m -k -nH -p --domains=yourblog.blogspot.com http://yourblog.blogspot.com
Now you can poke your blog with grep and all the other neat-o tools on your local machine.
UPDATE 20 April 2006: Since Blogger now supports uploaded images, here's the new recipe (which will fetch photos as well; note that the following should all be on one line):
wget -m -k -nH -p -H -e robots=off --domains=yourblog.blogspot.com,photos1.blogger.com http://yourblog.blogspot.com
Note that Blogspot puts my photos on photos1.blogger.com, but you may need to substitute whatever host Blogspot puts your photos on.