I was looking around for a sourdough starter a few weeks ago. As I just mentioned, it's a harvesting and prepping for the Dark Time feeling. I was thinking that I really needed to get a sourdough starter. Even though The Babe doesn't eat sourdough willingly, both Susan the Wonderchild and I do.
I looked online for recipes. I know you can create your own, but I was after something with a little provenance that was really good and sour. And lo! I found it in Carl Griffith's 1847 Oregon Trail Sourdough Starter. This is a culture from a sourdough starter that traces all the way back to the Oregon Trail in 1847. It was in Carl's family for the last 150-some years.
Carl was a generous guy who gave sourdough starter to any and all during his life and his friends have been continuing this habit now that he's gone. You can get enough sourdough starter culture to get your own sourdough starter going for the cost of an SASE. If you're thinking you aren't going to use it often enough, here's information on how to dry or freeze sourdough culture.
I'm still on the primary growth phase of the culture; I'll be feeding it with more flour and dried potatoes tomorrow. But it's growing nicely at this point and I've a container ready for it.