flickr2igal is a simple Python script to convert your Flickr sets into igal galleries. 
It downloads the original images if you have authentication.
Obviously, it requires that you have igal installed on your system.

Usage: keys-file set-name [options...]
    -u user
    -i igal-args keys.txt "My holiday photos" keys.txt "Someone else's holiday photos" -u HolidayMan -i "-r -f"

`keys.txt' specifies a key file that is available in the archive.

Currently the user (-u) option does not work because I'm lazy.

Words of warning:

Get flickr2igal here.