Accessories - Housewares - Finishing Touches - nailing without an hammer?

I got an hammer, but I got a reason why I don't wanna use it for this simple job.

I am trying to hang some portraits on the wall. The problem is the walls are solid. What i got is wood panels, but don't know what i have behind it. I was able to hammer some nails but with big difficulties and it was shacking the whole wall. My neighbor upstairs was wondering what I was doing, cause I was hammering so hard. I got many fragile ornaments on shelves and I don't want them to fall.

Is there another tool which would put my nails in the wall without hammering?

Use screws instead of nails ;)

.......or, drill a pilot hole just a tad smaller that tne nail and it will go in with minimal effort.

I use screws for hanging stuff on my walls. Worked esspecially good in our old home with plaster walls.