Using disposable plastic cups for parties is liberating in concept, but you may end up flogging yourself in the postmortem for this tacky hostessing cop-out. What’s the alternative? You could station yourself permanently by the sink, endlessly hand washing your crystal stemware for the steady stream of libations you serve between Thanksgiving and New Year’s Day. Or you could spend a small fortune on a service for 30. Instead, why not stock up on tumblers that are not only cheap enough to buy in bulk but also attractive, durable, versatile, and available over the Internet? Best of all, they’re dishwasher-safe, so at the end of the night you can let Whirlpool do the work while you kick back and savor your success.