Update: Gene Sequencing

A new data point just appeared in the news. 23andme.com, the personal gene sequencing company that Google invested in a while back, now offers their service for $399. Their original price was $1000.
This isn't a whole-genome sequence, but identifies about 500,000 SNPs (single-nucleotide polymorphisms) to give clues about roughly 80 personal characteristics.

The original price was offered on 12/04/2007, so I have calculated the price half-life at 0.77 years.

At this rate, a $99.00 offering will be due in about 2 years.

Price Half-Life for Gene Sequencing

Given the cost of a particular technology at two dates, you can calculate the half-life for the cost of that technology. Then, you can use the half-life to make estimates of that cost in the future.
For example, Moore's Law says that the price-performance of computer technology is about 18 months. That's the time it takes for the cost of the technology, relative to its performance, to halve. With a half-life of 18 months, one million dollars of computer power falls to $1000.00 in a little over five years.

I've just been able to calculate the half-life for sequencing a human genome. On 5/31/2007, James Watson was given his complete genetic sequence. It cost $2 million to decode. Today, Knome, Inc. is offering a complete sequence for $350K. From these dates and costs, I calculate that the half-life for the cost of this technology is 6.13 months.
Now I can extrapolate out to a $1000 genome. The answer is: 5.09 years from today.
We'll check back in a year or two (or when another data point occurs) to see how well this tracks.