Here's a couple of pictures from the last Great British Breakfast event.
http://www.englishforum.ch/photos/sh...user/1829/sl/f
Looking forwarsd to seeing fellow EF members there.
Afterwards you could probably go and visit the Swiss Folk and Schwingfest meet which is held nearby. It's really interesting and fun to watch or photograph.
Alternatively, if you have little ones with and a car, you could visit the Roggenhausen park which has deer, Vietnamese pot bellied pigs and other assorted animals to feed and stroke. I went there last week and the little ones loved it. They also have a restaurant and a kids play area with go kart track. It's on the left just as you leave the Aarau city limits heading towards Olten.