If you are an early bird, and even if you are not, consider taking the 5 am train up to Gornergrat so see the sun rise on the Matterhorn followed by a nice breakfast and a hike back down to Zermatt. The train passes once a week in the summer I think. Bring a sweater if you plan on staying outside long, I went in August and it was a bit chilly, even for a Canadian. You can also take the train back down if you don't want to hike, but the hike was incredible. I don't remember the cost though.