"Layaway is a method by which retailers allow consumers to make a purchase over time with the exchange of the merchandise coming at the conclusion of the payment period. This was designed by marketers as a way to sell more product. Consumers were having a hard time affording the items that retailers were selling, so retailers simply changed the way purchases were made. The advent of layaway was a coup for retailers following the Great Depression."
The above was from Peter Dunn's "When Old Tricks Become New Treats" and if your clients are looking for a way to help customers make purchases, can institute a system quickly, and have storage space at their location, Layaway may be an excellant way to entice customers to spend money with them...
"Layaway is back. When marketers were faced with the age-old question, "how can we get more people to buy more stuff?," they chose layaway. The interesting thing is that many people that fall into Gen Y aren't familiar with layaway's choppy history. This means that the previous reputation of layaway isn't a barrier to its rebirth. In fact, the old technique is so popular again that a new crop of online sites allows consumers to purchase goods from multiple retailers using online layaway. It's quite simple: you make payment to the website for a small fee, and your stuff arrives when your balance is paid in full. It is the perfect solution to what ails the American consumer (for the time being).
What ways are you coming up with to help your company sell more stuff to more people? Have you harkened back to yesteryear to find a source of motivation? Some retailers have as they make a final push to sell more stuff to more people this holiday season. Old tricks are new treats to newer generations. And, believe it or not, layaway may help retailers get into the black as this year comes to an end."
How hard is it to find a computer program that you can set up at your store? Some computerized POS systems have add-on modules ready to integrate with what you have. I googled "layaway software" and came up with several options. The first one is for your client's Yahoo store...
Download the free layaway software. Install Y-Cart to your Yahoo store. Configure your layaway settings (Minimum layaway amount, layaway fees, payment terms etc.) www.1choice4yourstore.com/aug-2006-ystore-news.html
This one if for clients that need something in store, they don't need to use the entire system, they can just use the layaway module and download, set it up, and advertise it before Black Friday...
Pos layaway software by Dave Proffitt and others 
ProffittCenter is an entirely free POS system for the small store with automatic ordering, stock checking and a stunning sales screen. www.freedownloadscenter.com/Best/pos-layaway.html