  Five nearby dwarf irregular galaxies, amongst the recently surveyed dwarf
members of the Sculptor and Centaurus A groups (at 2.5 Mpc and 3.5 Mpc), have
been imaged in neutral hydrogen (HI) with the Australia Telescope and the Very
Large Array. These objects have absolute magnitudes M_B in the range -14.9 to
-12.7, yet they are clearly rotationally supported, with maximum rotation
velocities ranging from 43 km/s to 67 km/s. Multi-component mass-models have
been fitted to the rotation curves. We investigate the properties of their dark
matter halos, and the scaling laws of the dark matter halos parameters.
