There's a shopping revolution happening--and it's taking place in stores, online, deep inside your wallet, and everywhere else transactions have traction. From the way we spend money, to the things we spend it on, to the sales outlets themselves, consumers are wandering in a wonderland of buying potential. PayPal's "digital wallet," Amex's slick socializing, Square's disruptive tech, Warby Parker's new way of selling eyeglasses, and Fab.com's, well, fab design site represent just a few of the people and companies at the forefront of the movement--and the innovations powering the way we shop now.

Warby Parker is a boutique online glasses shop that sells vintage-inspired specs for $95. In 2011, its second year, sales quintupled, and it has had to move offices four times to accommodate growth. Success, according to Neil Blumenthal (pictured here), came from not thinking like a LensCrafters. Read more here.

American Express may have finally developed a way to demonstrate a tweet's ROI--and not just in terms of commerce. The company recently unveiled a new program that lets cardmembers sync their accounts with Twitter, and earn savings from big brands such as Whole Foods, Best Buy, and Zappos--just by retweeting certain hashtags. Read more here.

Flavio Pripas and Renato Steinberg are the cofounders of Fashion.me. The site, which has more than a million customers, offers various customization options by busting apart designers' offerings, so women (97% of its users) can mix and match, dress virtual models, tag photos, and let others weigh in or suggest combinations. Read more here.

Among the new features being offered by the online pay giants is a "grace period" that allows you to switch how you pay for things within seven days of making a purchase. That means if you pay for an item with a debit card but then realize your paycheck won't arrive in time to cover your bills, you can log in to your PayPal account and tell the system to pay with a credit card instead. Read more here.

Anand Rajaraman and Venky Harinarayan are the Indian duo building social--and mobile--powered commerce products for Walmart Labs. Their Shopycat app looks at Facebook as a huge stream of data to predict what gifts your friends will like. Read more here.

"For decades, department stores were organized to have a center core of cosmetics, jewelry, and women's handbags," says JCPenney CEO Ron Johnson. "We're going to have something new called Town Square. It's a series of 80 to 100 shops." Read more here.

Fab.com started as a limping social networking site for gays but pivoted into a wildly popular hub for shoppers. Fab grabs them with a meticulously curated array of neat stuff. Before visitors know it, they're design junkies. Read more here.

Wrapp, which is backed in part by LinkedIn cofounder Reid Hoffman, allows you to send gift cards, which usually involve a certain amount of free money, like $5 or $10. The system syncs with Facebook, so when you want to send a gift, you select the recipient from your list of friends, and the service tells you what cards that person is eligible for. Read more here.

Meet Leslie Berland, SVP, Digital Partnerships and Development, for American Express. Berland's moment came through connecting Facebook to AmEx's "Small Business Saturday” promotion (an initiative to encourage holiday shopping with local merchants the day after the big-box-bloated Black Friday). Senior leadership initially saw social as secondary. "Facebook was going to be a side part,” Berland says. Read more here.

Corey Maass' startup, TheBirdy.com, sends daily email reminders to subscribers to keep them aware of what they are spending and where. Those shoppers then record daily purchases, slotting them into categories--food, entertainment, transportation, clothes––to see their progress on a graph. Like a feathered friend sitting on your shoulder, The Birdy can help you control spending and change your financial habits. Read more here.

There's a good reason Square is No.5 on our Most Innovative Companies list this year: The Jack Dorsey-helmed startup has grown to process about $4 billion in annualized payments, causing major players in the point-of-sale (POS) space like Verifone and NCR to race to launch their own alternatives. Read more here.