Don't be surprised if your kids come to you one day and ask what a tracking stock was. And don't be surprised if you struggle to find an example. Slowly but surely, these poster children of the go-go '90s are returning to the nest.

Over the weekend, Sprint (NYSE:FON) became the latest parent to call the paired listing home. According to Sprint, it will absorb its Sprint PCS (NYSE:PCS) tracking stock, giving owners of its wireless division half a share of the parent for each share of Sprint PCS.

Tracking stocks may have made sense in the 1990s when chunky corporate behemoths found themselves harboring rapidly growing subsidiaries. Tracking stocks allowed investors to benefit from the rapid growth subsidiary free of the anchor of the larger business.

Companies like Disney (NYSE:DIS) were among the first to reverse course, swallowing the tracking stocks for their Internet operations when the dot-com bubble burst. Telecom giants were next to bid a farewell to arms. WorldCom was absorbing its own MCI operations as the company buckled under two summers ago. AT&T (NYSE:T) may have followed suit with AT&T Wireless (NYSE:AWE), if it wasn't for a $41 billion buyout offer from Cingular Wireless last month.

Wireless was a booming sector just a couple of years ago. However, a cutthroat mentality has kept margins under pressure. Last November's move allowing cell phone users to move their existing wireless number to a new service provider will only make it harder to retain customers in the future.

Even so, this latest move won't come cheap for Sprint, which expects to maintain its quarterly dividend. Sprint PCS investors who once welcomed a lack of income distributions in the pursuit of wireless growth will now give Sprint more mouths to feed the stock's 2.8% yield.

So the tracking stocks have been derailed. Again. Well, at least until the next hot sub-sector emerges.

Do you think wireless portability will hurt service providers? What do cellular companies need to do to get back on the growth track? Were tracking stocks a trendy mistake? All this and more -- in the Wireless World discussion board. Only on

Longtime Fool contributor Rick Munarriz barely uses his wireless phone. He does own shares in Disney but of no other companies mentioned in this story.