Locked deep inside everyone are intimate secrets about health, behavior, and appearance—mysteries that until now have remained hidden since humans first appeared. Now, for about $1,000 anyone can find out online if he or she has a high or a low risk of diabetes or heart disease, or a gene for wet or dry earwax.

Do people want to know the DNA responsible for their hair and eye color, or information about where their distant ancestors came from?

Two of three high-profile gene-web companies plunged humanity into a new wave of direct-to-consumer genetics this weekend—at least, those humans who are "DNA-curious" and willing to shell out a cool grand.

On Friday, deCode Genetics of Iceland introduced "deCodeme", and on Saturday 23andme of Mountain View, California—funded in part by Google—rolled out Personal Genome Service. A third newbie company—Navigenics, backed by the mega-venture firm Kleiner, Perkins, Caufield and Byers—is coming soon. Online genetics pioneer DNA Direct is another major competitor. It has offered individual DNA tests for diseases since 2003.

The two sites I've seen so far look similar, but there is a difference. 23andme is a pure 2.0 software play, while deCodeMe comes from deCode Genetics, a publicly-traded, decade-old gene-discovery and drug company famous for using the Icelandic population to mine for genes associated with disease. In the last year, deCode has regularly made headlines around the world as they discovered genes associated with several common diseases such as diabetes and heart attack.

"When you compare us to other companies, we have discovered many of the genetic tests available," deCode C.E.O. Kari Stefansson said in a telephone interview from Reykjavik, Iceland. "We have an unrivaled competence in understanding and analyzing this data because we have been doing this for years."

"We recognize the great work that deCode has done," responds 23andme co-founder Linda Avey, "but no one person or company can claim to have ‘the real goods on genetic information'." Her company has assembled an advisory board that includes  experts such as Harvard geneticist George Church and Stanford bioengineer Russ Altman.

Navigenics falls somewhere in between. Its senior managers and advisors come from both the web world and biotech. They also plan to charge more at the moment, about $2,000 for healthcare information only.

The arrival of these genetics companies represents a fusion of the wild and wooly Web 2.0 and the stodgier world of genetics and health care. At first blush, the new websites look user friendly and even fun, with the company's offering customers rafts of information about themselves (after they send in a DNA sample in a spit container or on a cotton swab).

First is DNA that's purely fun, such as which band of hardy Homo sapiens you belong to that left mother Africa eons ago, or whether or not you have the "sprinter's gene" that makes you dash faster than those with a different variation of this gene.

The other category is far more serious. These are the nucleotide time-bombs hidden inside you that may change your life—genes associated with dread diseases. They may increase the risk of getting cancer, heart disease, Alzheimer's, or diabetes. This information is fraught with issues and pitfalls, not the least of which is that the science of genetics is very young and not entirely ready for the bold consumer lunge into consumerism.