Like the rest of America, CBS execs apparently are realizing that their reality dud, Big Brother, is, well, a big bore. Hoping to shake things up a bit — not to mention boost the show's disappointing ratings — the network may have one of its Survivor castaways pay a visit to the Big Brother prison, er, compound, the New York Post reports. The crossover could take place anytime in the next 10 weeks. Last night on Survivor, college student Jenna — in a close vote — became the latest contestant booted off the island. (Nudist Richard missed being cut by a single vote.) And on Big Brother, the housemates nominated stripper Jordan (for the second time) and Big Apple attorney Curtis for banishment. Meanwhile, Survivor executive producer Mark Burnett reportedly has issued a restraining order against a viewer upset that the reality soap showed participants eating rats. Donna LaPerch allegedly sent Burnett threatening e-mail messages.