Actually, there are systems that have negative (absolute) temperature, and "a system with a truly negative Kelvin temperature is hotter than any system with a positive temperature".
These are strange systems that can absorb only a finite amount of energy. When they are almost "full" of energy, their temperature is negative. (For simple systems the negative temperature appears when they have more than the 50% of the maximal energy, but it depends on the system.)
This can not happen in normal systems. For example an ideal gas can absorb infinite energy, because the molecules can go faster and faster.
http://en.wikipedia.org/wiki/Negative_temperature
These are strange systems that can absorb only a finite amount of energy. When they are almost "full" of energy, their temperature is negative. (For simple systems the negative temperature appears when they have more than the 50% of the maximal energy, but it depends on the system.)
This can not happen in normal systems. For example an ideal gas can absorb infinite energy, because the molecules can go faster and faster.