  We investigate the interaction of tightly focused light with the
surface-plasmon-polariton resonances of metal nanospheres. In particular, we
compute the scattering and absorption ratios as well as transmission and
reflection coefficients. Inspired by our previous work in Ref. [1], we discuss
how well a metal nanoparticle approximates a point-like dipolar radiator. We
find that a 100 nm silver nanosphere is very close to such an ideal oscillator.
Our results have immediate implications for single nanoparticle spectroscopy
and microscopy as well as plasmonics.
