臨機応変

Excite翻訳: Flexibility
＠nifty翻訳: Adaptable
Babel Fish: Opportunism
Google翻訳: Circumstances
Yahoo!翻訳: Adaptation to circumstances
OCN翻訳: Adaptation to circumstances
Windows Live Translator: 臨機応変

Summary:
Excite and @nifty choose one word while Yahoo! and OCN explains the meaning,
all of which describe the correct situation.

Reverse Translation)
Excite翻訳: 柔軟性
＠nifty翻訳: 適応可能
Babel Fish: 便宜主義
Google翻訳: 状況
Yahoo!翻訳: 状況への適合
OCN翻訳: 状況への改造
Windows Live Translator: 臨機応変

Summary:
@nifty's describes the situation shown by the original expression,
while it seems that noun or noun phrase sometimes provide different nuances.