For me, there's a slight difference in the de in both words, but it's really really hard to get across in text. The best I can think of is dessert is deeh-zert, and desert is deh-zert.

"You need me. You wouldn't be much of a hero without a villain. And you do love being the hero, don't you. The cheering children, the swooning women, you love it so much, it's made you my most reliable accomplice." -- Lex Luthor to Superman, Question Authority, Justice League Unlimited