I like doing new things. Drive (not recommended, but it is a fucking experience),
ride a bike,
swim (shallow water),
canoe,
climb a tree (slowly),
try a hand stand,
try to balance in a new position,
play (with a) piano,
listen to 3 different genres of music you've never tried before,
draw with a permanent marker,
break stuff with a baseball bat (nothing precious),
lay in the grass and watch the plants and insects,
Watch a really shitty movie or something like C-SPAN,
Listen to a TED talk or something,
and all of the above posts.
I really like the feeling of learning that I get when I'm tripping. When I learn something new while tripping I basically master it. It's a wonderful deal.