Edit March 8, 2013: The Internet Archive has a better set of scans of Swete. It includes options for direct download of the files in various formats, including images.
The Christian Classics Ethereal Library hosts [scans of H.B. Swete's "Old Testament in Greek According to the Septuagint."] It is a public domain LXX, including introduction and textual apparatus. If you find yourself desiring to store the images on your computer instead of viewing them through CCEL's website, you can use this Python script which I created. It will grab all of the PNG files of the text and apparatus and arrange them in order, by volume.
The script itself is not much, but I decided to license it under the GNU General Public License, version 3. This script uses some Python 2 syntax, so I might convert it for Python 3 at some point (though it's not so great a taks). If CCEL decides to change the structure of their site, it may break this script.
I considered hosting the finished product here, and may do so in the future, but for now I am going to preserve the bandwidth.
[scans of H.B. Swete's "Old Testament in Greek According to the Septuagint."]: http://www.ccel.org/s/swete/?show=worksBy