Damped Lyman-? systems (DLAs), the highest HI column density absorbers seen in QSO spectra, are believed to arise in the precursors of present-day galaxies [1]. Despite their importance in the context of galactic evolution, the typical size and structure of DLAs (as well as physical conditions in them) have long been issues of much controversy. Radio studies of DLAs in the redshifted HI 21cm line provide a new dimension in our understanding of the absorbers. For example, if the QSO behind the DLA is radio-loud, 21cm absorption studies can be used to probe the kinematics, temperature and distribution of the absorbing gas. Conversely, 21cm emission observations allow a direct determination of the HI mass of the absorber, as well as its physical size and velocity structure. In this article, we describe recent progress in such radio studies, primarily based on work with the newly commissioned Giant Metrewave Radio Telescope (GMRT).