There are many tools for backing up Blogger blogs to Windows but none I could find for us OSX and Linux users.
Here is a PERL script that will fetch your rss feed from your blogger blog. It will grab your posts and save them with the same name as on blogger. It will then fetch the images from your posts and down load them. Files are stored in a separate directory for each month.
Comments are not downloaded with this script.
If you have Perl installed on your computer then down load this file.
Chmod 755 BloggerBackup.pl to make it executable
On line 38 change the 999s to your blog’s blogger id number
Then run the script.
./BloggerBackup.pl
If you have more than 300 posts change the max=300 to a number larger than the number of posts you have posted.
If you have a slow net connection or tons of images it will take a few minutes, be patient. Otherwise it is very fast.
More information:
Download Perl and help to get you started
You may need to install Perl modules; see How to install Perl modules
See also:
Perl Script to back up Blogger comments