model a shape something like a raspberry I am trying to build something like this. Is there a nice way without just snapping spheres to vertices? It could be interesting to look at using the Fibonacci sequence also to distribute the spheres.
Take a look at Dupliverts, that allows the duplication of a base object at the location of the vertices of a mesh. In other words, when using DupliVerts on a mesh, an instance of the base object is placed on every vertex of the mesh.

Or try the Tissue add-on by Alessandro Zomparelli

It allows you to copy a selected object (Component) on the faces of the active object (Generator), adapting its bounding box to the shape of quad-faces.



Thread on Blenderartists.org with more examples here