壁に耳あり障子に目あり

Excite翻訳: The ear is on the wall and it is in the shoji eyes.
@nifty翻訳: Walls have ears
Babel Fish: There is an ear in the wall and there is an eye in the shoji
Google翻訳: The sliding door in the walls have ears
Yahoo!翻訳: Walls have ears Shojis have eyes
OCN翻訳: There is an ear on a wall and there is an eye in a sliding paper door.
Windows Live Translator: Ear to the wall and Shoji eyes and

Summary:
@nifty's is a normal expression.
Yahoo!'s additionally has the latter half, but "Shojis" may not be understood.
Babel Fish's is a direct translation but sufficiently makes sense.

Reverse Translation)
Excite翻訳: 耳が壁にあります、そして、それは障子目にあります。
@nifty翻訳: 壁に耳あり
Babel Fish: 壁に耳があり、障子に目がある
Google翻訳: 壁に耳がついているスライドドア
Yahoo!翻訳: 壁は、耳Shojisに目があらせます
OCN翻訳: 壁に耳があり、スライディング紙のように薄いドアに目があります。
Windows Live Translator: Shoji 目、壁に耳と

Summary:
@nifty and Babel Fish reproduce the original expression.