"They're great for people like myself that are always on the go," said Duffy.
Duffy logs on to the growing number of stores offering online gift cards, picks the amount she'd like to spend, enters her credit-card info, the recipent's name and e-mail address, and her shopping is done.
"Buying a virtual gift card is super-easy to do," said Duffy.
Unlike traditional gift cards, virtual gift cards can be instantly sent and spent online. Some businesses let you print out your certificate and even spend it at the store. And other retailers offer apps where you can actually save your gift-card points to your mobile phone and have the cashier scan it at checkout.
"Retailers see a tremendous potential in the use of virtual gift cards to attract new customers and to reward loyal customers," said Karen Renk, executive director of the Incentive Marketing Association.
Industry experts say virtual gift cards are the hottest trend in shopping and social networking. Many stores are giving them away to Web customers who visit their Facebook and online fan pages.
But there are some pitfalls to online gift-giving. Duffy actually received one once, thought it was spam and deleted it.
She and her gift-giver had to battle with the retailer to get it reissued. Spam filters can be a real virtual gift-card "Grinch."
"If the e-mail doesn't arrive it's like the gift hasn't arrived," said Gail Hillebrand, senior attorney, Consumers Union.
Consumers Union suggests giving your recipient a heads-up you sent them an online gift card so it doesn't become virtual junk mail.
If you ever lose your virtual gift card code or printout, call the retailer immediately. It may be able to re-issue you a new one with the amount of value remaining on it at the time you report it.