This was taken in 2006
This was 2007
This is from last week. It's getting tall, but what really excites me is that it's making some kind of buds. I read somewhere that this cactus rarely flowers, and the flowers are sterile, so I'm very curious as to whether it will actually bloom, and what the flowers might look like.
Here's a bud. It's tiny, but there are several sprouting up all over the length of the cactus. The buds are attracting ants, and I even saw an aphid on a bud this afternoon. (Why didn't I take a picture? I don't know.)
I will update with more pictures as the situation warrants.