If you've got kids set this up for them as it's great fun for them. It really got my two going all day. They have watched Santa fly around the world with Norads Santa tracker, which can be accessed via the following site. You do need Google Earth installed:
http://www.noradsanta.org/en/home.html
It works on both IE and Fire fox (I've just installed Fire fox for the first time in three years due to that problem. Now I may just stay with it as I was immediately impressed at how the bookmarks were ordered and also several other things. Old habits die hard and it's taken a message from Microsoft themselves to make me change over - I wonder how many IE users they will lose once the problem has been fixed?