Over in Japan, Logitec just released its Nexas line of external USB 2.0 hard drives that feature what the company calls the "ASC Method" of cooling. The ASC Method senses when the hard drive is getting too hot then flips on a fan in the hopes of preventing some sort of Three Mile Island-like disaster. Two models are available, the LHD-HD and the LHD-HBS, the latter of which includes beefed up security options to keep your data safe from prying eyes. (The world must never know of your affinity for watermelons.)
Both hard drive models are available in 250, 300, 400 and 500GB sizes, with the security-conscious LHD-HBS costing around $430.