[lvknight]

We lived in a 3 bed 2 bath 1100 square foot house that was built around '79-'80. With that old of a house, our utilities were kind of high. Original doors and windows, newer a/c unit.
Power...350/mo high, 70/mo low. Thermostat set at 82 from 7:00 am to 3:00 pm, 3-8 79, from 8pm to 7 am 76.
Gas....150 high, 50 low. t-stat in winter never above 69. Gas dryer, water heater, furnace, stove/oven.
Water...25/mo. 2 adults, 2 kids, desert landscaping, front loading washer.
Cable...About 150. That includes phone, internet, hdtv, dvr, and a few pay per view movies a month. No premium channels (HBO, etc.).
Sewer depends on if your in Clark County, Las Vegas, North Las Vegas. But plan on around 50/quarter.

We now live in a 3 year old 1700 square foot house. Its a 2 story with one a/c unit. Cable, water and sewer are the same. With the same thermostat settings the power and gas are:
Power...250 high, 45 low.
Gas...135 high, 35 low.
As you can see, the age of the home made a huge difference. An older home with upgraded windows, doors, insulation, and a/c unit would probably be a lot closer to a newer home for utility costs.