(Amendment to Details Below: We'll be meeting at the above time and place at the rendez-vous point: the blue sign, "Fergene til øyene". Then we'll be heading to the main island, Hovedøya. Feel free to bring a picnic blanket or games like kubb!)
I was thinking that since the weather has warmed up and the sun's out most days, there should be an island run for this meet-up group. There's good fun to be had on a day excursion to one of the islands in the Oslo Fjord (Hovedøya, Langøyene or Gressholmen). They're great for picnics or taking a dip.
Hovedøya is the largest and most popular island, with the ferry running most frequently to it than any of the other islands.
Langøyene allows for overnight camping for those who want to stay over. In the summers, I read that it's nice to camp out without a tent.
Gressholmen has a small restaurant that serves sandwiches, dinners and beers if we want to go that route instead.