I'm considering what, but I have less than 5 minutes.

Play harmonica.

Nice option! I had it as a child, but I never really learned it, it became a toy.

What most new players don't think about is how the shape of your hand around it plays a large part in the sound that's made. Once you start playing with that, you can soften the tone, and have more control of the output. Not many instruments can fit in a pocket. If you find songs in the same key as your harmonica, it's fun to play along and improvise.

My dad got me a Hohner harmonica when i was a kid and i LOVED it.

That's the brand I have. They're great! I think my first one is nearly worn out. I'm tempted to buy the same model to listen to the difference.

That was my first official musical instrument. I would love to play some blues stuff on it now that I understand a little bit more since I can noodle around on the guitar a bit.

Get a harmonica in the key of G for blues! It's a common blues key.

I was thinking of D because my guitars are tuned to DADGAD and I could record some riffs and play along

Great idea!