The Moon is approximately 1/2 a degree in diameter when you look at it from the surface of the Earth. Of course, the moon is pretty big, it's just fairly far away (~238,900 miles). Here's an image that shows the scale of the Earth-Moon distance:
To help give us a sense of how large other planets are, artist & illustrator Ron Miller decided to create a series of images in which he replaced the Moon with what other planets would look like if they were as close to Earth as the Moon.
First, here's a picture of the Moon from the Earth:
Now, here's Mercury (which just looks like a big Moon):
Jupiter (now that's a spectacular sight):
No Pluto for you! (though I would be interested in seeing the image...)