2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/14085We summarise some aspects of experiments currently being built or planned, and indulge in wild speculation about possibilities on the more distant horizon.18 pages, 4 figures, 2 in colour, uses paspconf.sty, to appear in "Microwave Foregrounds", eds. A. de Oliveira-Costa & M. Tegmark (ASP, San Francisco, 1999), minor corrections to some numbers and figuresAstrophysicstext