As you well know, today is March 14th – aka “Pi Day”.

Celebrated in math classrooms around the country, this truly is a celebration that belongs to the geeks. Here at Hack-a-Day, we too love Pi day, though we might not outwardly celebrate it with as much gusto as expressed by some of our readers.

[Chris Poole] is one Hack-a-Day fan who knows how to make the most of this mathematical holiday. He has put together a neat SIP-based phone service that reads Pi aloud to anyone who calls. He is running Asterisk in combination with Perl to read off the numbers, and is using a free SIP DID number to accept the calls. We gave it a shot earlier today, and were greeted by a gentle synthesized voice reading off the numbers of Pi. We’re not sure how many digits it is programmed to handle, as we stopped after about 20, so give him a call and let us know how many digits you make it through.

As a parting note, no Pi Day would be complete without a few obligatory Pi-related (albeit old) web comics and pastry concoctions, so here you go!

XKCD – Pi Equals…

XKCD – e to the Pi Times i

XKCD – E to the Pi Minus Pi

Spherical Pi Pie

[kayakdiver] is developing a SIP and PUFF controlled kayak, but in order to start you first need a SIP and PUFF switch. These devices allow the user to lightly sip or puff into a tube to control switches or sensors, and are sometimes mounted in joysticks for control of a computer, or wheelchair, etc, but finding the cost prohibitive the next best thing was to whip up their own.

The design is clean and direct featuring off the shelf tubing and fittings, 2 pressure/vacuum switches, and an Arduino. Each one of the switches can detect pressure or vacuum, so one switch set to each is fed though a Y and up to the mouthpiece, since everything is sealed this has the advantage of only needing pressure and not airflow making it more comfortable for the user over long periods, and keeps down on humidity in the tubes.

[sprite_tm] made my morning by sending in his latest work. After opening up his new SMC WSKP100 (Skype wifi phone) to identify the hardware differences, he managed to shrink a flash image from the SMCWSP100 to fit on his new toy. Then he spent some time hacking the kernel from the former to work on his phone. The result? A SIP operational phone that’ll connect to his asterix server at half the price of SMC’s official SIP phone.