Now some fresh pickings from the Political Grapevine:

Global Warming Bet

An internationally known expert on forecasting methods is challenging Al Gore to a bet over his prediction of global warming temperature increases.

Marketing professor Scott Armstrong of the University of Pennsylvania's Wharton business school is offering to put up $10,000 in a bet for charity.

The wager would involve Gore's forecasts against what is called the "naive model" — in which temperatures basically would stay the same.

Armstrong believes most climate change forecasts use bad methodology. He says the bet is meant as a way to provoke debate.

Armstrong says he hasn't gotten a response yet — and Gore's office did not return a call from us asking for reaction to the challenge.

Insecurity & Narcissism

A new psychological profile of Venezuelan President Hugo Chavez says he is driven by insecurity, malignant narcissism and a need for adulation.

George Washington University psychologist Jerrold Post did the workup for the U.S. Air Force. He says of Chavez — "He views himself as a savior, as the very embodiment of Venezuela. He has been acting increasingly messianic and so he is likely to either get the constitution rewritten to allow for additional terms or eventually declare himself president-for-life."

Venezuelan law currently prohibits Chavez from seeking a fourth term, but he has indicated he might seek a change that would allow him to run again in 2012.

Sex-Change Operation

Massachusetts prison inmate Robert Kosilek — who is serving a life sentence for murdering his wife — is suing the state in order to get a taxpayer-funded sex change operation.

Kosilek legally changed his name to Michelle after the murder — and insists that hormone therapy and counseling have not given him relief from gender identity disorder.

His advocates say the operation is as much a medical necessity as treatment for diabetes or high blood pressure.

But the state corrections department is fighting back hard — spending more than $52,000 so far on experts to help them avoid paying for the $20,000 operation.

The state argues that if Kosilek has the sex change procedure he would become a security nightmare and a target for sexual assault.

Candidate Dinner

Florida firefighter Jennifer Lasko is one of four people picked to have dinner with Barack Obama next month in Washington. She won the spot after writing an essay explaining her political transformation from Reagan conservative U.S. Army soldier to anti-war liberal Democrat.

Then The Palm Beach Post reported that Jennifer Lasko had another transformation — she used to be John William Lasko — and underwent a sex change operation two-and-a-half years ago.

Lasko has since offered to bow out of the Obama dinner. But an Obama spokeswoman says Lasko is still welcome to come and the decision is up to her.

—FOX News Channel's Martin Hill contributed to this report.