Thanks to Dr. James Adams for identifying this moth!  It is quite common in my yard in the summer.  My photographs date from mid-June and September, and it seems like it was out all summer long.  The flowers are tiny, the moth nearly as tiny, and this summer I will try and estimate their length, at the very least from comparison with the bluet flowers.

June 15, 2004, near Greenwood, Wise County, Texas

Same individual as above, with a friend.

June 15, 2004, near Greenwood, Wise County, Texas

June 23, 2004, near Greenwood, Wise County, Texas

June 19, 2003, near Greenwood, Wise County, Texas