Next in the line of projects that could inspire you for Valentine's day is this interactive creation by Instructables user blinkyblinky. They've created the typical LED heart with some LEDs which can be used in various displays or perhaps worn for fun, but instead of just creating blinking or fading patterns the designed has wired a pulse sensor to the controlling Arduino board.
With this the data from the sensor can be used to blink the heart's LEDs in time with the user's heart rate - allowing for something that can at least be a conversation piece for the special day.
This project can be adapted for more serious or interesting uses, such as an inexpensive heart-rate monitor or toy lie-detector. For more information on how to reproduce your own version, visit the project page. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
If you're interested in experimenting with Arduino for your own inventions - but not sure how to learn - order one of our Experimenter's Kit for Arduino:
The package includes a wide variety of parts, sensors and modules including: a servo motor, lights, buttons, switches, sound, sensors, breadboard, wires and more. Furthermore a Freetronics Eleven Arduino-compatible board is included to make this an extensive hobby experimenter, inventor and starter kit.