Yesterday I realized that I didn't have enough research material for the book I'm currently writing. The protagonist was about to visit Chicago in the 1890s, and while I know a little bit about that subject, I don't know enough to write competently about it. I didn't have enough in the research books I own, either. So today it was off to the library -- three of them, in fact -- and while I was doing that I realized that after the guy leaves Chicago he'll be going to Boston, and I didn't know enough about that, either. I rounded up books on both subjects and have already figured out a plot point about the Chicago scenes that was bothering me, so the research certainly helped. Between the library visits and a few other errands, I didn't do any actual writing today, but I ought to be able to get back to it tomorrow.
And of course, I found a stack of books that I just want to read, too, which is one of the perils of going to the library. I hope to get to them soon, since it seems like all I've been reading lately is research for one project or another.