

Since you at least know the layout. Typing of the Dead can be fun for forcing you to start using more fingers as things come at you. I needed to force myself to get better in order to make sure I could pass a timed typing speed and accuracy test for a data entry job. Played it a little every night for at least a week before my interview. I was still kind of slow, but was much more accurate. Which got me into a position that corrected or found missing information from the main data entry folks. If arcade zombie games aren’t your thing, there are some other good games mentioned in the other comments.
The Thunderbird team is actually looking to bring it back as part of their new (paid I believe) services along with Thundermail.