A while back, I came across a great list in Chesapeake Life called 25 (Chesapeake) Things To Do Before You Die. I've done quite a few of the things on the list, and there's a few more I'd like to try (Southern Maryland stuffed ham doesn't seem to get up to Baltimore much). Realizing how much time I've spent thinking about the rest of the world, I thought I would add a few annotations for my own hometown.
With summer coming up, I think the top item that's missing from their list has to be egg custard snowballs with marshmallow on top, a treat that's native to Baltimore.
"Learn to sail" is on their list, but it's pretty easy to get onboard local racing boats with a little experience. Local magazine Spinsheet hosts a meetup party every year to match crew with ships, and you can walk into the Boatyard Bar & Grill in Eastport any Wednesday night in season to watch race replays with the locals.
And finally, they mention the annual (and very well-known) "Punkin Chunkin" contest in Delaware, where contestants attempt to launch pumpkins extreme distances using homebuilt cannons, but they don't mention the very cool Maryland Delaware Rocketry Association, which is out on the Eastern Shore nearly every month launching some huge, amateur built rockets.
Those are just a few things that I've done or seen in the last few years. There's a lot more out that that becomes apparent when you start remembering that it's OK to be a tourist in your own hometown.