  Star formation in interacting systems may take place in various locations,
from the dust--enshrouded core of Ultraluminous Infrared Galaxies to more
unusual places such as the debris of colliding galaxies expelled into the
intergalactic medium. Determining whether star-formation proceeds in the latter
environment, far from the parent galaxies, in a similar way as in spiral disks
has motivated the multi--wavelength study presented here. We collected VLA/HI,
UV/GALEX, optical Halpha and MIR/Spitzer images of a few nearby interacting
systems chosen for their prominent "intergalactic" star formation activity.
Preliminary results on the spectacular collisional HI ring around NGC 5291 are
presented.
