1. Vancouver, Canada
2. Tijuana, Mexico
What's Nearby: San Diego is about an hour away, Palm Springs is about a three-hour drive, and it'll take about four hours to get there from most parts of Los Angeles.
3. Niagara Falls, Canada
What to See: You can't go wrong with seeing Niagara Falls in Niagara Falls — no matter what time of year. But there's also Clifton Hill, a whole neighborhood full of exciting things like the Skywheel, dinosaur- and wizard-themed miniature golf courses, and a roller coaster.
What's Nearby: Besides Niagara Falls, New York, it'll take less than an hour to get there from Buffalo, less than two hours from Rochester, and about three hours from Syracuse.
4. Matamoros, Mexico
What's Nearby: It's right across the border from Brownsville, Texas, but farther jaunts include an over three-hour drive from Laredo (if Nuevo Laredo, Mexico, isn't in the cards for the day) or an under three-hour drive from Corpus Christi.
5. Montreal, Canada
What to See: See?! You need the poutine, the coffee, the bagels, the seafood, the foie gras... OK, fine, the Parc du Mont-Royal has delightful views as well. When you're not eating.
What's Nearby: Burlington, Vermont, is about two hours away, and Watertown, New York, is about a three-hour jaunt.
6. Monterrey, Mexico
What to See: The views throughout the city cannot be beat, but it truly outdid itself when it converted old steel factory grounds into Parque Fundidora.
What's Nearby: It's about a three-hour drive from either McAllen or Laredo, Texas.
7. Winnipeg, Canada
8. Chihuahua, Mexico
9. Québec City, Canada
What to See: The Carnaval de Québec in late January/early February features snow sculptures, events, and almost too much fun. But if you're not there in winter, Plaines d'Abraham boasts breathtaking views all year.
What's Nearby: Burlington, Vermont, is about 3.5 hours away, while Augusta and Bangor, Maine, are about 4.5 hours away.
10. Nogales, Mexico
What to See: During any season, Nogales has the best authentic Mexican food, drink, and music you crave.
What's Nearby: Tucson, Arizona, is about a 1.5-hour drive, and you can get there in about three hours from Phoenix.
Thanks to T-Mobile's Mobile Without Borders, you won't get charged extra for calling or texting anywhere in North America...which means you're pretty much out of day-trip excuses.