The Solar and Heliospheric Observatory (SOHO) was launched in 1995 and is positioned in a stable orbit at a point between the Earth and the Sun, where the gravitational forces of the two bodies exactly cancel each other. Consequently, the SOHO is fixed in space between Earth and Sun, and thus is at a prime position to monitor the Sun:).
As comets orbit around the Sun and once in a while crash into it, the SOHO takes their pictures. Scores of volunteers pore through the videos from the craft, and often are the first to spot new comets. Toni Scarmato, a high school teacher from Italy, discovered SOHO's 999th and 1000th comet recently, when two comets appeared in the same SOHO image:):).

The twin comets (Courtesy: SOHO)About 85 percent of the SOHO comets discovered so far belong to the Kreutz group of sun grazing comets, named because their orbits take them very close to the Sun. SOHO's 999th and 1,000th comets also belong to the Kreutz group. The Kreutz sun grazers pass within 500,000 miles of the star's visible surface. In contrast, Mercury, the planet closest to the sun, is about 36 million miles from the solar surface.
SOHO has also been used to discover three other well-populated comet groups: the Meyer, with at least 55 members; Marsden, with at least 21 members; and Kracht, with 24 members. These groups are named after the astronomers who suggested the comets are related, because they have similar orbits.
Almost all SOHO's comets are discovered using images from its Large Angle and Spectrometric Coronagraph (LASCO) instrument. LASCO is used to observe the faint, multimillion-degree outer atmosphere of the sun, called the corona. A disk in the instrument is used to make an artificial eclipse, blocking direct light from the sun so the much fainter corona can be seen. Sun grazing comets are discovered when they enter LASCO's field of view as they pass close by the star.
A large animation of the comets can be found here.