the polar cap melting thing has always baffled me - so I ran some numbers. Note that the north pole is a floating ice cap so I've ignored it in the figures. The south pole is an ice sheet over land.

Ocean Surface area of the earth: 361 million km^2
Required Volume of water to raise the oceans 200 feet (.06 km): 22+ million km^3

The south pole has roughly 14 million km^2 of ice surface area and if we were to just look at the contribution of the south pole, the ice would have to be 1.6 km thick (above the water) to contain 22 million km^3. Reportedly (Wikipedia), there is 30 million km^3 of ice on the south pole alone - but I don't know how much of this is ice cap, ice sheet, or submerged.

Greenland's ice sheet surface area is a little over 1.8 million km^3...throw that into the volume calculation and the average ice thickness above the surface for Greenland and the South Pole would need to be 1.4 km thick.

Obviously, there's some more ice in Russia and Canada, so let's just toss in the whole surface area of Canada to approximate them both. Now the average ice thickness above the surface in Greenland, Antarctica, and Canada (assuming completely covered evenly) would be .8 km thick.

Basically, it's not as outrageous as I first thought (assuming that ALL of it would melt - dunno how practical that really is).