In the last decade it has become clear that the 21 cm H I line can be used to probe the neutral intergalactic medium at high and low redshifts. This is one of the main scientific motivations behind a number of modern radio telescopes e.g. the Square Kilometer Array (SKA).
In this talk I will discuss why it has become feasible to detect the local cosmic web through this emission with currently, and soon to be, available radio telescopes. The detection of H I in the cosmic web will constitute a milestone in studying the large- scale structure. It will have significant implications on important issues, such as the missing baryons in the cold phase at low redshift, the dynamics and topology of the cosmic web, and gas-galaxies interplay. | 
