Surrounded by Spiders! New Black Widows and Redbacks in the Galactic
  Field
  Over the last few years, the number of known eclipsing radio millisecond
pulsar systems in the Galactic field has dramatically increased, with many
being associated with Fermi gamma-ray sources. All are in tight binaries
(orbital period < 24 hr) with many being classical "black widows" which have
very low mass companions (companion mass Mc << 0.1 Msol) but some are
"redbacks" with low mass (Mc ~ 0.2 - 0.4Msol) companions which are probably
non-degenerate. These latter are systems where the mass transfer process may
have only temporarily halted, and so are transitional systems between low mass
X-ray binaries and ordinary binary millisecond pulsars. Here we review the new
discoveries and their multi-wavelength properties, and briefly discuss models
of shock emission, mass determinations, and evolutionary scenarios.
