Download Google Earth, the popular virtual globe program, and use its elevation feature. In the 3D viewer, the elevation of the point directly under the cursor is displayed in the lower-left corner of the screen in terrain view mode. To change between feet or meters in the elevation display, go to "Options" under the Tools menu and select "3D View" before clicking on the "Show Elevation" radio buttons.
Use Daft Logic's Find Altitude script for Google Maps. This is an online application that will tell you the elevation of any point on the earth, accurate within a meter's height, at a single mouse-click. It's a free service, so, while Find Altitude doesn't come anywhere near a surveyor's level of accuracy, it's a good alternative.
Try the National Map online Seamless Server. This is another online application, run by the U.S. government. It's much more accurate than Daft Logic's tool, though somewhat more complicated to use. The user interface is reminiscent of the internet of the late 90s, but it's both functional and extremely precise.