I think I would include a lot of non electronic things like photographs and writings along with a letter explaining that I didn't include much technology because I couldn't predict it would still work or be powered in 100 years.

I think I would also include a map to a great treasure that I just made up because I enjoy messing with people!

I would also include money. I don't know that I would include CDs, but probably, as some others have suggested, electronic devices that we use today, which will surely be completely obsolete by then. I would also include some sort of message, perhaps a brief written explanation of ourselves- what we're afraid of right now, what our priorities are, how we feel about the big political questions of our day, etc. 

I would suggest clothing styles which are popular. I love to see the older clothing styles from past generations. I would also suggest pictures of things which are popular now (musicians, artists, etc.).

I think you would want to include popular devices that are used a great deal today.  Things like iPods and smart phones and such.  But be sure to put in hard copy instructions of what they are and how to use them because they will be relics in 100 years.