Have dirty deeds left your company with a tarnished reputation? A quick name change might be in order. If onetime mobsters can enter witness protection and emerge with shiny new names and spotless identities, a redesigned logo and a new moniker might help give muddied companies a similarly fresh start. That's not a big deal -- unless you find yourself fooled by that benign new name, and end up invested in a company you don't like.

Scrub away that oily stain
In the wake of the Deepwater Horizon disaster, observers have argued that BP (NYSE: BP) should change its name -- perhaps to Amoco, which it acquired at the end of 1998. If it does, the company wouldn't be the first to try on a fresh identity.

Consider Altria (NYSE: MO). Investors are rightfully attracted by its steep dividend yield (recently near 7%) and its fairly reliable revenue and earnings. Not everyone will realize off the bat, though, that Altria is the former Philip Morris. Even among those who do, the new name still puts a little mental distance between the company and the concept of cigarettes.

Yum! Brands (NYSE: YUM) enacted a more subtle change when it rebranded its Kentucky Fried Chicken operations as "KFC," thereby helping investors and consumers associate the chain less with fatty fried foods. Since the company has been offering healthier fare recently, the move does make some sense. Indeed, its grilled chicken has been a huge hit for the company, quickly accounting for 40% of on-the-bone chicken sales.

Meanwhile, Comcast (Nasdaq: CMCSA) is keeping its corporate name (for now), but rebranding its cable services with the "Xfinity" name. Some might suspect that change stems partly from the company's desire to distance itself from a dubious reputation for customer service. But Comcast insists that as it makes its service more digital, its new technology merits a new brand name as well. In a recent discussion with analysts, management noted that 65% of its customers are already aware of the new name.

Urgency-driven changes
Sometimes a company will change or tweak its name for more urgent reasons, such as an ongoing scandal. I wouldn't be surprised to see that happen with BP. Anything to put some mental distance between it and the massive oil spill from its rig will likely be good for business.

As you do research, make sure you know whether a company has entered the corporate equivalent of a witness protection program. At the very least, you'll get a fuller picture of the stock and its history -- and a better sense of how it deals with disasters and challenges.

Corporate history is littered with name changes and name tweaks. Do you remember a particularly interesting or amusing one? Let us know -- leave a note below!