Shopping, particularly extended shopping (an hour or more) includes some of the very same exercise moves that you loathe at the gym: walking for extended periods of time, lifting objects of weight, and if you're trying on lots of clothes there's squatting, over-the-head reaches, and any number of other odd movements you might make trying to get a good look at yourself in the mirror.
Don't believe me? I looked up some information on shopping as exercise - every woman's dream - from Nutrition ATC and found an article that backs up what I'm talking about. In an article found on their site (originally published by StarBulletin) they state that a 200lb person can burn as much as 750 calories during a 3 hour shopping trip at the mall just by slowly walking from store to store and standing in line. They also note that a "super shopper" who is more active (fidgeting in line, picking up and inspecting merchandise, waving to friends or flustered mall staff) may burn an additional 100 to 250 calories during the same time-span.
All that adds up to a workout that can't be found ordering Christmas presents online. Who needs a better excuse to get out and get shopping? A word of warning though - avoid the food-court lest all your shopping exercises be undone by pretzels, cinnamon rolls and fried foods. I'll see you there!
(And I promise to try to find an hour somewhere in my day to do some yoga too.)