I've not been on an Alaska cruise but here are a couple of suggestins.

In Juneau he should see Mendenhall Glacier at the edge of town. There's an interesting visitor's center with a short film and a couple of hiking trails to get you up close. Also in Juneau is the Mt. Robert's tram to the top of Mt. Roberts. It needs to be a clear day though. If it is he will get great views of Juneau. Great visitor's center, restaurant, don't miss the short documentery in the theater, several hiking trails.

When he gets to Anchorage he should take a side trip to Denali to see the wildlife and the mountain.

I know its not much but I hope it helps.