If you own a house or other real estate, you no doubt spend at least a little of your time wondering what you could get for your house if you tried to sell it today. While you'll never know for sure unless you're out there on the market, every so often I like to check out two of the "Web 2.0" real estate sites that offer estimates of home values.

Zillow is my favorite for this. Type in your zip code and then use the controls to narrow the search to your street. Then you can get numbers on houses for sale and recent sales in the area, plus you can get a "Zestimate" of the value of your home, even if it's not on the market. (If you don't see your house when you narrow it down, use the "Most Popular" feature on the left side to get more listings to show up.)

I'm not entirely sure I buy the "Zestimate" for my own home, but Zillow says that half the time they're within 10% of the sell price. Of course this means that half the time they're not even within 10%, which could mean their estimate is many thousands of dollars different than what your home is worth. Nevertheless, between their estimates and the actual recent sales, it's a good way to get a ballpark on how your home is doing and how the neighborhood is doing in general.

Trulia offers something similar, allowing you to see current "for sale" properties as well as recent sales and have them all plotted on a map. It doesn't give you an estimate of your own home's worth, but since any estimate is only an educated guess, you can use the comps of homes similar to yours and take a stab at your home's worth.

Of course any estimate of your home's worth versus anybody else's can't take into account the overall condition of the homes-you're really using only quantifiable criteria, such as square footage and/or numbers of bedrooms and bathrooms, etc. If you've ever done any house hunting, you probably know all too well that one 3-bedrom 1.5 bath home can be very different from another.