Today, I tested it to make sure that the gasket made a good fit, and to determine what heat level I need to put the burner at once I have pressure up. I am pleased to report that it worked well, and being one of the weight style canners, I didn't have to worry about getting a gauge calibrated.
I have been reading up on canning things I've never tried canning before, such as bread, cake or butter. Yes, I know that the experts say don't do it. For example, at the University of Georgia, some experts did a study on canning cake. They took some bacteria that they knew isn't killed by high temperatures, deliberately introduced it to the cake batter, baked and sealed it, unsealed and tested it. The report does not actually state that the cake was subsequently processed in a pressure canner. Naturally, the heat-resistant bacteria survived the experience.
And yet, you can buy canned bread!
Similarly, the experts advise against canning butter because of botulism. For example, you can read the material from the National Center for Home Food Preservation, University of Georgia on this topic. However, they do not address the matter of those who recommend processing the canned butter in a pressure canner with the same directions one would use for any fatty meat/fish product. No actual research has been done on canning butter.
So, what it boils down to is that you have to decide whether or not you will take a chance with these canning practices, keeping in mind that some botulism cases have actually been caused by commercially canned goods. Back in the day, people were aware that there were dangers inherent in the canning process. Nevertheless, before the advent of electricity and freezers, it was the best method available for storing foods. So, people took their chances.
Before canning, a lot of the methods of storing foods over the winter involved caching food in a cellar, or a hole in the ground, or a cave, or an unheated building. A lot of this food suffered from the depredations of rodents, who not only nibbled on the foods, but left behind disease-ridden calling cards, and fleas (which also carried diseases). They frequently didn't have clean water to drink, and didn't know why they got sick.
We do know about these disease vectors, and so we can work to overcome them, but the bottom line is, life is not really safe.
My personal take?
Update: May 2011 - after doing more research, I'm looking into making and storing ghee. Once the milk solids have been removed from butter, clarified butter or ghee, can be stored for a significantly longer time. Check out this article here (a .doc file).
Or butter powder: