There is a huge variety among the real estate markets of the United States, with some geographical areas pretty cheaply priced, and some that are incredibly expensive. To put this in perspective, let's take a look at what a half a million dollars will buy you in different parts of the country.

Source: Trulia.
Miami, Florida
Miami is one of the few urban areas that features year-round tropical weather and is located right on the ocean. The majority of homes in Miami are condos, and for $559,000, you can buy a two bedroom, two bathroom condo on the 49th floor of a high-rise that has 1,198 square feet and beautiful views of the Atlantic Ocean, Biscayne Bay, and the port of Miami.

Source: Trulia.
However, if you are willing to live a few miles inland, there are plenty of single-family homes to choose from, like this five-bedroom, four-bathroom home in nearby Coral Gables, where the University of Miami is located. The $459,000 asking price features almost 2,500 remodeled square feet, and is just a short drive to all the hotspots.
Alexandria, Virginia
Just minutes from Washington, DC, Alexandria is a very desirable location for those who want to be close to the city, but want a more "spread-out" feel. For under $500,000, you can get a three-bedroom, three-bathroom fully renovated townhouse/condo like this one. The 1,471 square-foot home also has a one-car garage, a balcony, and a small fenced yard.
Source: Trulia.

Source: Trulia
Columbia, South Carolina
I chose to include Columbia not only because it is a market that I am very familiar with, but because I wanted to show how much house can be bought in markets that are not in the major metropolitan areas. The capitol city of South Carolina is home to about half a million people (in the greater Columbia area), has a nice downtown area, major universities, and one of the largest man-made lakes in the country.
In the $500,000 price range, there are some pretty impressive homes to choose from. One good example is this 4,200 square foot, five-bedroom, five-bathroom brick home on a pond. Your half-million gets you a chef's kitchen, bonus rooms, a screened porch, and almost an acre of land.
Las Vegas, Nevada
Las Vegas is particularly interesting because it was one of the hardest-hit markets by the real estate downturn. It has recovered some, but homes in sin city are still much cheaper than they once were.
$489,900 could buy you this four-bedroom, four-and-a-half-bathroom home that is just under 4,000 square feet and a short drive to the famous Las Vegas Strip. The home features a pool, upscale kitchen, and built-in BBQ in the backyard. According to Zillow, the home was worth almost $900,000 before the bubble burst.
Source: Trulia.

Source: Trulia.
New York, New York
The short answer to "what does $500,000 get me in New York City?" is "not very much." A half-million dollar budget is very low, especially for those who want to live in Manhattan.
For those budget-conscious home seekers who insist on living in this extremely desirable area, there are a lot of studio apartments available, like this 482-square-foot example. While it's certainly possible to look a little bit outside of the city and get a little bit more for your money, if you live in Manhattan, how much time will you really want to spend at home?