Question:    Are ethers polar?

Answer:

Diethyl ether is a polar molecule.  If you draw out the Lewis structure, you'll find that the electron density tends to move from the ethyl groups toward the oxygen due to the differences in electronegativity.  Since there are only two electron donating groups, the molecule is polar in much the same way that water is polar (though less so, as the molecule is larger and the ethyl groups themselves are fairly nonpolar).

For the same reason, ethers in general are polar.  Also, as a general rule, the larger the groups stuck to the oxygen, the less polar the ether.