GEO, MEO and LEO ... What in the universe are these?

During the past few years the vision of global mobile personal communication systems (GMPCS) via satellite has become a reality. Unfortunately, due to various reasons, two of the three GMPCS satellite companies experienced financial problems. Both Iridium and ICO filed for chapter 11 bankruptcy. The third company, Globalstar, is moving forward slowly while waiting to receive the go-ahead - for example an operating licence for the Southern African region. Eagle River Investments (Teledesic) invested into ICO since its systems have close synergies with Internet in the sky, This means the technology developed is here to stay and [1] GEO, MEO and LEO satellites are part of this technology.