The so-called hyper turbo tournaments have blind levels going by every two or three minutes, with only a handful of hands played on each blind level. As blinds go up so fast, players become short-stacked very fast, and push-fold poker is more common than in any other game format.
A typical standard online tournament blind structure increases every 10-20 minutes. The actual speed depends on a number of factors including the tournament's buy-in. Turbo blind structures tend to increase every five or so minutes, with hyper-turbos being even crazier, raising the blinds every three-minutes or so.