On "Seinfeld," Elaine hoards the contraceptive sponge and decides whether a man is "sponge-worthy" before using one. The storyline centers on the Today Sponge, which Elaine treats as a scarce and valuable supply after it is taken off the market.
The plot unfolds in season seven's "The Sponge," which aired on December 7, 1995. Elaine refuses to switch birth-control methods, visits multiple stores, and eventually buys 60 sponges from a pharmacy. She then carefully evaluates her boyfriend Billy before deciding whether he deserves one of her limited supplies.
The joke was rooted in a real product shortage. The Today Sponge was a plastic contraceptive device containing the spermicide nonoxynol-9. It had been removed from the U.S. market amid manufacturing and regulatory problems, making Elaine's frantic search recognizable to contemporary viewers. The product later returned to American stores before eventually becoming unavailable again.
A common mix-up is to answer "Today Sponge" when the quiz asks for the generic contraceptive. "The sponge" is the canonical answer in the episode, while Today is the brand name. The phrase "spongeworthy" became one of the show's best-known expressions.