The Calculated Risk

Antique Vintage R.C. Allen Model 805
Mechanical Adding Figuring Machine
Buy it (as of 2014-01-19) for $99.95
from gwenna_baker on eBay

Harwell’s 1951 WITCH & IBM 305 RAMAC, 1956
Gadgets and Design blog

Woman at old computer terminal
CarrieBradshawIsFullOfIt.com

Tektronix Model 31 Electronic Calculator
Old Calculator Museum

Vintage Texas Instruments
The Little Professor Electronic Calculator
from braegsalot on eBay

Spreadsheet screenshot
OS2ezine.com (really!)

Modern desktop computer
mosup.com

Scientific Calculator desktop app
eeweb.com

Calculator Cell App
CellPhoneForums.net

Solar Flare
LiamScheff.com