For years, consumers in Asia and Europe have had electronic coupons beamed to their cell phones. But in America, says Peter Fuller, executive director of the Mobile Marketing Association, "we're just now starting to think of the mobile phone as not [only] a communication device, but a centralized entertainment/commerce/ scheduling appliance." In March, McDonald's teamed with tech firm Gamut Industries for a promotion offering people in Oregon and Washington mobile coupons (and free cell-phone wallpaper and ringtones). Media company Enpocket teamed with Dunkin' Donuts to do a mobile promotion for its latte among Boston-area high-school and college students; 17 percent of those who got the coupons (there's an opt-in process) redeemed them. Marketers hope they'll soon be able to send coupons based on location: walk by a Starbucks, say, and get 50 cents off a mocha Frappuccino. Tasty idea.