I bought the I-Dog for my son, but it turns out that this is a neat little fellow and I use it, too. When you first open him, he is in puppy mode and he has to learn his personality, according to the type of music you play. He will display emotions, such as bored, sick, ecstatic, happy, normal, lonely, and sad. You have to make sure you "feed" him with music and give him attention.
The I-Dog dances to the beat of the music. You can either plug an MP3 player directly into him, or he will respond to music playing in the room. Even when not playing music, he will interact a bit. Sometimes he will even bark at you. Don't mess with that tail!
The sound quality is decent. What I like most about it is that if I am working late or working at home, it is a small speaker I can put next to me and continue to work, without putting the earbuds in my ears. I adjust the volume control on my IPOD.
You need a screwdriver to install the batteries. The IPOD cable also fell out on me several times, so I make sure I push it all the way in.