I'm really glad Oberon pointed this out. Comet Holmes just appeared - bright even in Bostonian skies - in Perseus (which is next to Casseopeia, the "W"-looking constellation). Here's how to find it. J-Fav and I found it in less than a minute with binoculars. Have fun!
I did a lot of stargazing in high school, and I admit this is a really funky one. It doesn't have a tail; it's big and white and fuzzy, in front of a backdrop of its pinpoint star neighbors.
(You'll need binoculars for this, unless you have good clear dark skies that will let you notice it's fuzzy.)