The TSA website crowed, "Explosive-Like Item Intercepted at Checkpoint."
Gizmodo and Boing Boing and others pointed out that it's (a) a metal water bottle and (b) a homemade battery, with a wire strung between them for no good reason.
Quoting from the TSA report:
"The item in question was determined to be an empty metal bottle and a home-made battery pack, consisting of 28 rechargeable batteries connected by multiple resistors and held together in two layers with a silicone-based adhesive.
"The passenger was an engineer and said he built the battery to power his DVD player for the long flight to Hawaii. After recognizing that the item could be seen by other passengers as a threat, the man surrendered it to Supervisory TSO Raiford Patterson and was allowed to board the flight."
[UPDATE: The TSA has copped to the error. Where the article used to be is now a statements from Ellen Howe, who is "responsible for the content of this website. We obviously had a lapse of judgement on this story and you folks in the blogosphere have done a good job of keeping us honest.... A suspicious-looking item is not the burden of proof for surrender of said item. This looks much more like the Wylie Coyote bomb of yesteryear." To see the full statement, click here.]