I just bought a book YESTERDAY called "501 TV-free Activities for Kids" with things to do starting at age 2. It was on the "Bargain Books" shelf for only $5.99. It looks pretty interesting and I can't wait to use some of the ideas.
Also, while growing up we would play what my mom called "The Traveling Alphabet". When we were really little, she’d have us find things with the letter sound. For example, “Can you find something that starts with ‘a’ like apple?” (Then “b” “c” …) as we got older “can you find a word that starts with ‘a’?” (Then “b” “c” …) You get the picture I’m sure. We would play every time we got in the car, walked to store, went grocery shopping, when ever. It was such a part of travel with me that the first time my hubby and I took a road trip, I taught him to play. Now every time we’re driving more than about 30 minutes away, we play. Our two year old is starting to pick it up as well! (Just the “I found a car! Kah, Kah, Car!”
Hope it helps! -J