One of the reasons cities all over the world grow to huge sizes are the number of opportunities available for their populations. The more opportunities available, the more people will move there. Conversely, the more people living in a city, the more opportunities become available, so that big cities tend to grow larger over time. Anyone who has a zip code in Houston Texas knows this to be true; the population of this city has exploded over the last century. Today it is the fourth largest city in the nation and a world beta city, with employment opportunities ranging from work with lead shot manufacturers to the service industry.

The driving force behind Houston's growth is definitely the energy sector. Houston is the city that gave Texas its reputation as a major oil producer; five of the six major oil companies in the world have major headquarters located in the city. Oil is big business and companies truly have money to burn; that is good news for anyone looking for work in the city. Companies such as Apache Corporation and Citgo are always on the lookout for people to work on rigs, in production packaging through the work of an automatic banding machine, and other areas.

While energy is the biggest business in Houston, it is certainly not the only one. With the tenth largest port in the world and the largest port for intentional commerce in the United States, transportation and shipping is a major economic sector within the city of Houston. It's the place where an on demand hot water heater made in South America is likely to cross the border into the States, and of course much domestically produced oil is internationally shipped from here as well.

Petroleum is also important in the manufacturing sectors of the city. Much of the world's oil equipment is built right here in Houston, providing thousands of jobs for skilled and unskilled labor alike. Much of the SR&ED which drives oil exploration is also done in the city; this research base has expanded to include areas of biotechnology as well.

Finally, you can't have that many high paying jobs without them spinning off into even more opportunities for city residents. If you want to start your own construction business, Houston might just be the best place to do it. With an economy growing even in a recession and a location where high gas prices are actually beneficial, it is a city where employment prospects are high.