Play a computer game (scrabble, mah jong or bridge for me), read a book or magazine, do crossword puzzles or sudoku, listen to music, watch a movie, write in a journal, play a board game, or answer questions here on yahoo answers. Cook something, clean the house, go for a walk, work out, call a friend, send emails, visit someone, or even go shopping.
Writing in a journal is an interesting thing to do, especially when you go back weeks or months or even years later and read what you wrote. Buy yourself an interesting blank journal that represents who you are, and start writing your daily thoughts, ideas, and important events. You'll be surprised at how quickly you will look forward to the time you spend with it each day. And it could become a powerful record for posterity.
Look for a new hobby. Find something that is of particular interest to you. Possibly you might like to begin researching and compiling your family tree. I am sure many members of your family would encourage you with a project such as that. A couple of other things that come to mind that I have found interesting in the past, and they now occupy my grandchildren are learning to do origami (read the story about Sadako and the 1000 paper cranes, and maybe start a paper crane project of your own), and another is learning to tie different knots (most book stores will have a book on the different knots, and it is quite interesting, and also a very useful skill to have).
Take a class - learn the finer points of digital photography, painting, writing short stories, small appliance repair, playing bridge, dog grooming, pottery, home maintenance, carpentry, plumbing, quilting, scrapbooking, or anything else that is offered in your area. Often you can find classes that are free, or almost free.
Finally, and probably most importantly, if you find yourself bored often, consider volunteering. It will give you a new focus in your life, and it is a good feeling to help someone less fortunate or more in need than yourself. It can be a life changing experience.
Boredom is a choice you make, not a state of existence. If you are bored, it is because you are allowing yourself to be bored. Look around you. Most likely you have books, and a wide variety of other possessions. Look at the things around you and think of ways to use them. If there are people around you, think of ways to help those people. Think of others and how to help them, not yourself, and you will never be bored.