  Swift is shedding new light on the phenomenon of Supergiant Fast X-ray
Transients (SFXTs), a recently discovered class of High-Mass X-ray Binaries,
whose optical counterparts are O or B supergiants, and whose X-ray outbursts
are about 10000 times brighter than their quiescent state. Thanks to its unique
automatic fast-slewing and broad-band energy coverage, Swift is the only
observatory which can detect outbursts from SFXTs from the very beginning and
observe their evolution panchromatically. Taking advantage of Swift's
scheduling flexibility, we have been able to regularly monitor a small sample
of SFXTs with 2-3 observations per week (1-2 ks) for two years with the X-Ray
Telescope (XRT). Our campaigns cover all phases of their lives, across 4 orders
of magnitude in flux. We report on the most recent outburst of AX J1841.0-0536
caught by Swift which we followed in the X-rays for several days, and on our
findings on the long-term properties of SFXTs and their duty cycle.
