NEW YORK (CNNMoney) -- The typical way to buy stock in a publicly traded firm is to open a brokerage account and place an order. But for those who want to own just one ceremonial share of a company, there's an easier, if sometimes pricier, way: You can buy through websites that specialize in "one share" transactions.

The operators of those sites say they expect Facebook to become one of their most popular stocks once it begins trading publicly. That's currently on track to happen this Friday.

"It interests people who are not ordinarily interested in the stock market," says Rick Roman, the founder of GiveAShare.com. "We've been getting people asking about it for a year."

Sites like GiveAShare.com and OneShare.com are careful not to market themselves as places for serious investors. Stocks are risky, and any gains on a single share are likely to be tiny.