Pace of technological innovation

Good source of various measures of the rate of change of technology
Was Moore’s Law Inevitable?

Cooper's Law

Much like Moore's Law deals with the growth curve of transistors and integrated circuits, Cooper's Law, named after Martin Cooper, discusses the performance curve wireless communications.  Specifically, the capacity of usable spectrum doubles every two and a half years.

However, there are indications what new mobile technologies (LTE) are approaching the Shannon limit (pdf link, page 10, section 4.3).

What happens when that limit is reached: smaller cells and more spectrum are needed to meet the demand.

Performance Curve Database

Need data showing how the performance of something has changed over time?  Head over to the the Santa Fe Institute's Perforance Curve Database site that has graphs and data describing such things as the historical performance of photovoltaic cells (think efficiency,  cost per watt, etc).
Below is the graph of Hard Drive storage over time