The June issue of Discover Magazine has an interesting article on the Russian Фобос-грунт (Phobos-Grunt, "Phobos-soil") mission which is currently planned to launch in October 2009 (there is some indication that it could slip to the 2011 Mars launch window instead). This mission will land a probe on the larger of Mars' two small moons, Phobos, pick up a small "soil" sample, and return it to Earth. The article by James Oberg is called "Stepping Stone to Mars" and is now available online.
How is this a stepping stone to Mars? Well, Phobos is an interesting little place. It orbits Mars every 7.65 hours, with one side always facing Mars. This could be a good spot for observing Mars, with radiation protection provided by both Phobos and Mars. Astronauts at a base on this side of Phobos could tele-operate rovers and other surface machinery without the 10-20 minute lightspeed delay faced by Earth-based operators. Phobos is also relatively easy to get to in terms of orbital mechanics "delta-V" (energy), about the same as landing on Earth's Moon, much less than landing on Mars itself. Of course there's a lot of science that needs to be done to determine what sort of object Phobos actually is before we start putting up buildings there.
The material picked up by Phobos-Grunt may also tell us something about the early history of the solar system, or about Mars, or maybe both. If water ice is detected in or on the small moon, it could make Phobos even more favorable as a possible future base for exploring Mars.
The Phobos-Grunt mission will also carry a special experiment from the Planetary Society. It's called LIFE (Living Interplanetary Life Experiment), and it will send a small collection of hearty Earth microbes sealed inside a tiny canister to see how well these simple life forms are able to survive the conditions of interplanetary space over some 34 months. The canister will be attached to the soil return module so it can be studied back here on Earth. This will provide a test of some aspects of the "panspermia" theory (life possibly traveling between planets embedded within meteors) by showing whether or not these organisms can survive these conditions. We know that bacteria can survive in the most severe conditions on Earth, and we have experience with relatively short near-Earth space exposures during which many bacteria have done just fine. Strep and perhaps other bacteria survived 31 months on the Moon inside parts of the Surveyor 3 spacecraft which Apollo 12 astronauts returned to Earth.
Of course this all assumes that this Russian mission launches for Phobos in 2009 or 2011 and makes it there safely. The Russians have had rather poor luck with Mars missions in the last 50 years (first try was October 10, 1960). They are zero for twenty. I hope Phobos-Grunt breaks their losing streak on Mars.
There's a YouTube video on the Phobos-Grunt mission (good graphics and animations, but only Russian narration).