Ctrl, Shift, Downward Dog

Imagine having your very own personal yoga instructor around every time you're in the mood to get into Tree Pose. Now imagine that the instructor isn't a flesh-and-blood yogi, but a computerized voice gently saying things like: "To begin, practice Mountain Pose for 10 breaths. Feel the natural curve of your lower back and the even grounding of your feet against the earth."

And there you have iYoga. The new software application by Software Studios combines modern technology with ancient practice by way of a virtual instructor that delivers voice-synthesized guidance through the various asanas, or poses.

The program gives instructions for an asana, waits a specified number of breaths, sounds a chime, then proceeds to the next pose. Because users can control each word iYoga speaks, they can tailor their routine to their own needs, thus going beyond the more generic instruction and music of yoga CDs and DVDs. The iYoga software goes for $34.95 and is available on Amazon.com, exclusively for Macintosh OS X.

Since guidance is delivered as synthesized speech, there's no need to look at the computer, a book or television while practicing. And since iYoga works as a word processor, users can bring any words they want into their practice. The spoken text blends with background music played by iTunes, so practitioners can mix their Hanumanasana with some harmonies.