Disecting small animals (cats, fetal pigs etc) has helped me get a general idea of practical anatomy. For me it's all well and good to learn something from a book, but actually seeing and touching what you've been talking about is the best way to learn. As far as usefulness goes, I'm a pre-med major so disection has a two-fold purpose for me. As we continue disecting more and more complex animals it shows me that I will be able to handle myself when I go to disect a cadaver. It also builds a strong base of practical knowledge that I can draw on. Not everything will be the same, but seeing the similarities will be very beneficial.