Lynn,
Is he interested at all in computers? A laptop would be ideal, if he is. This is assuming he will be able to use his arms/hands? A tape recorder works great for someone who needs to amuse themselves. He could start a life journal by recording what he would want his 4-year old son to hear, later in life. He could also learn a foreign language by listening to CD's. Music is another option and a valuable one. It soothes the savage beast and my guess is, after about a week or so of being bedridden, you are gonna want to kill him or vice versa...hehe...A jigsaw puzzle is great entertainment and if you buy "theme" puzzles, like Marilyn Monroe (for the beast in him) or Mickey Mouse (to decorate your sons room with later, after he works it and glues it together) or ELVIS! He's still alive you know...anyhoo...just some suggestions.