Anything with a handle old purse gym bag etc. even plastic bags just double them up and add anything to them. Dirt rocks whatever. Work on the major muscle groups like legs shoulders back etc. use the bags just like you would dumbells. Remember that any kind of exercise is better than doing nothing!
I got a great one for you. A pvc pipe diameter arround 10 to 15 cm. And arround 1 meter long but you can get a thicker one/larger one to increase the weight. Fill it up for about half or what ever is heavy for you. Make sure to close the ends very wel.
Pipe can be used for squats, lunges, holding it in the arms while walking(bicep) and what ever you can figure out with it.
The weigt of the pipe wont be real heavy but the constant moving of the weight will make you work really hard to control it. Makes for a cheap exersise equipment.
When I was in Iraq we used 5 gallon buckets and filled with sand at different levels for weight. Plus using duffel bag filled with sand and I use at home to for clean n presses. Its dead weight and great for the core.