The Old Calculator Web Museum

Remember that old paper-tape calculator your folks used to do their taxes? Or the crazy beige 70's calculator your high school math teacher insisted on using? Well, those look positively modern compared to what you'll find at The Old Calculator Web Museum, an extensive collection of vintage math machines.
The calculators in this online collection range from simply antiquated to utterly bizarre. Others look like they're taken from early NASA programs (surprise -- the Wang LOCI-2 was indeed used to test space suits at NASA). Some of the calculators have cool styling, like the Facit 1111, which shows its numbers in a hip, tilted typeface.
The museum also features an Advertising and Documentation Archive, which is a hoot. The ad for a Mathatronics Mathatron 8-48 calculator read thus (emphasis added):
"They laughed when I sat down to play the Mathatron." "Little did they realize then that this was no ordinary $5,000 Mathatron. All they could see was the simple algebraic keyboard, and the paper tape readout. "But underneath the Mathatron, cleverly disguised in the table, was capacity bringing the totals to 48 individually addressable storage registers, 480 steps of program memory, 18 prewired programs of 48 steps each, increased speed, and added program control! "By my right hand, unknown to those snickering on my left, close by the candelabra, was an additional control box which told me, by blinking lights, which of the 10 loops I was addressing. And there were other buttons there, too. "When I finished my evaluation of the formula involving trigonometric, logarithmic and other functions, matrix manipulations, triangulation and the solution of polynomials, they applauded generously." Send for complete details.
Other notable calculators: Hewlett Packard HP-01 Calculator Wristwatch (the gold version went for $795), Wang Model 360SE Calculator System (which featured high-end math functions at a low price -- as well as awesome Nixie Tube displays), and Toshiba BC-1211S Electronic Calculator (which omitted the division function to save money).
Check out the museum to satisfy your retro calculator fetish.