Technically not the best way to do it but you can use Point to Surface Constraint (set to weld, 0 rest length) to pin a cube (or any shape) to a vert on the cloth object, with .0001 mass, high resistance settings to make it semi-rigid, turn Off collisions (although On can make some interesting fx) and basically constrain the object then make it an emitter. Tweaking other parameters such as giving the nParticles collisions with the cloth its emitting from, can give you some cool results…all depends on what youre exactly after.
Rivet will do it fast and easy, but using ncloth you can get some out of the box results that may result in some cool fx ;)
here are 2 quick test - change the 2nd constraints Strength and Tangent Strength back down to 20 or so and itll sim alot faster, but the cube wont rest as tightly on the surface...
or you can change it to Spring and make the cubes mass much larger, to create a dangling object that interacts with the cloth, the constraint and itself all in the same dynamics system… many different things you can do with this method