The Hasbro iDog reacts to music - it does not download, record or store music. Instead you can plug it into an external device such as an iPod or other mp3 player and play your music through the iDog's speaker. Alternatively it will also react if placed near a speaker when playing external music.
The main response of the iDog to music is to flash its seven multi-coloured LEDs according to the beat of the music playing. It also moves its head from side to side and wags its ears.
Depending on the type of music to which it is exposed the iDog will develop one of several "personalities" - these influence its primary choice of colours to display. It also has a few sensors and can react to these with vaguely doglike barks or growls.
The iDog is available to buy in various colours including black, white and pink. If you want different colours or just a different look then you can buy the i-DOG Chill set - fashion accessories including sweater and hat!
If dogs aren't really your thing then you can also buy the iCat (i-CAT) or iCy (I-CY) the penguin!
Again, I'd stress that this isn't really a robot or even a robotic toy - movement is extremely limited. However it is a very cool gadget.