Autograph Suggestions

We are going to Disney for the first time in about a month.

My kids are unexpectedly excited about autographs, but I don't want to get a book for them because that seems kind of pointless to me. I saw a photo mat idea (have the characters sign the mat, then put a family pic in the frame), but I'm not sure how I feel about lugging around a photo mat for the whole trip.

Does anyone have any fun/semi-useful autograph collection ideas?

Also, we are doing a lot of character meals (I think 4) because we did the Dining Plan and it's our first time going to WDW, but do characters even sign during the meals?