  A novel scheme is presented for generation of a multipartite W state for
arbitrary number of qubits. Based on a recent proposal of entanglement without
touching, it serves to demonstrate the potential of particle
indistinguishability as a useful resource of entanglement for practical
applications. The devised scheme is efficient in design, meaning that it is
built with linear optics without the need for auxiliary particles nor
measurements. Yet, the success probability is shown to be highly competitive
compared with the existing proposals (i.e. decreases polynomially with the
number of qubits) and remains insensitive to particle statistics (i.e. has the
same efficiency for bosons and fermions).
