It was a lot of fun to carve different faces into the pumpkins and it's all HTML5. I tried it on my iPad and it didn't really work (I could select a pumpkin, but not carve it.) so this ecard isn't perfect yet. Remember that tablet computers like iPads are only gaining in popularity, so forgetting to test your applications in them can be a mistake. But it's still a fun example of what you can do with HTML5.
Be sure to play with this outside of work, as there is sound that starts automatically. It's easy to turn off, but it's there. My office mate asked me what I was doing the minute I flipped to this page.
Have you built an HTML5 site? Or do you know of one that does a great job with HTML5? Submit HTML5 site designs to be featured on this site.