Buster's trick 'o the day: He actually used the litter box! He didn't poo when I took him for his morning walk, so I was resigned to finding a mess on the floor when I got back from my errands this morning, but instead there was a big pile of uncovered puppy poo in the litter box.
Whenever he hasn't been able to hold it before, he's almost always gone in the bathroom, and usually near the litter box—clearly he caught on to the fact that that was the correct place for going inside—but actually going in the box is a first. I have such a crazy smart boy!
ETA: OMFG. My entire apartment complex is gated, so when I take the garbage out, I often let Buster come with me without putting him on his leash. Except just now, he (and I) figured out that the slats on the gate door are wide enough for him to get through, and he went through and TOOK OFF. I sprinted after him, but he was already a block away, running wildly and paying no attention before he dashed into the street. Apparently he just needed to poo again, so I was finally able to catch up to him while he was squatting, and then pick him up and carry him home, but holy fuck, I was so terrified watching him run so fast and so far and paying no attention to cars. NEVER LETTING HIM OFF THE LEASH EXCEPT IN OFF-LEASH PARKS EVER AGAIN. God, I'm still shaking. I really thought I'd lost him.