First off, ROAD TRIP! Plan to spend the summer driving across the country rock climbing, hiking, camping, surfing.
Then, lots of rock climbing (including guiding), ice climbing, snowboarding (possibly instructing), surfing, scuba diving, hiking, camping, and jiu jitsu, both domestically and internationally. Once the DW retires (likely 5-7 years after me), we'll slow travel to places we like, where I can also do the above-mentioned things. I'm thinking 2-3 months at a time in places like Mexico, Costa Rica, Thailand, etc., then 2-3 months at home, rinse and repeat.
I will also be looking for volunteer opportunities, probably with the elderly. I have this idea of visiting nursing homes and hospitals to play cribbage with seniors. My grandmother used to LOVE to play cribbage with me -- right up until she passed away at 95, when I'd ask her, "Meme, would you like to play cribbage?," her eyes would light up and the biggest smile would break across her face. It gave me so much satisfaction to sit and play with her for a few hours, and I know it meant the world to her. Another idea I have is to start a rock climbing summer camp for disadvantaged or at-risk kids.