I've been fooling around with an adjustable free weight at home, and forcing myself to do a few (12-15) pushups, bicep curls, or plank hold every night before I let myself go to sleep. It's no substitute for a gym (hence why I found I was so much weaker lol), especially with only one or two sets, but it's nice to keep my hand in.
It's also nice to know I can hold a plank position for 5 minutes without stopping.