Groundhog's day is a great holiday because it's a festival of desperation in the face of a long winter. I'd say that's just what's needed now. It's not a federal holiday; nobody gets off work (except maybe in Punxsutawney); and we don't have any special foods to eat or prepare. But after weeks of gray, snow, sleet and ice, I love that we have a marker day. You either get six more weeks of winter or else 42 days (do the math!).
To find out more about Groundhog's day, you can visit a number of websites. I actually thought Wikipedia's article on Groundhog Day was the best I looked at. They cover the European origins of the holiday, where folks in the old country looked at a variety of hibernating mammals, from hedgehogs, to badgers to bears (yikes!-- I'm glad we only look at a sleepy little marmot!). They reproduce the old Scottish rhyme about telling the weather til spring by the weather on Candlemas Day. And they have links to all kinds of related articles from Imbolc (Irish celebration of the first signs of spring), to various climate centers, famous groundhogs and even to all kinds of fictional treatments of Groundhog's Day.
Groundhogs are actually awfully cute little animals. It's hard to find a picture to do them justice. A lot of images look suspiciously like prairie dogs to me. We've had groundhogs in our yard -- they can't resist fallen peaches, apparently, and they look like little toddlers in baggy fur jammies. Right up until they see you, and then they have a surprising turn of speed -- hard to believe something with such short legs and a baggy, slumpy appearance can go that fast! Image of a groundhog found at http://www.dailypepper.com/mt/archives/000084.html but I suspect they nabbed the picture from elsewhere.