One great thing about taking a train versus other transportation is that you can enjoy the sights. Bring a camera to take pictures. Depending on where you go you can even see some famous landmarks like the Washington Monument in D.C.
Taking a trip on a train is also a good time to catch up on reading. Bring a few books, depending on the length of the trip you might be able to make it through a whole book.
Reading and looking out the window can get boring, but another fun thing to do is to play some games. Mad Libs, a fill in the blank word game can be really fun to play even if you are alone. If you have some travel companions you can also bring some small games like Battleship or a deck of cards.
Listening to music is a great way to pass the time. If you bring an MP3 player you can listen while doing other things like read or take pictures.
Bringing a laptop computer and a cell phone are fun ways to keep in contact with other people or to get work done while traveling. Trains make occasional stops in town so you may be able to get internet and most cell phones will get service while on the train.
