Or do it on the cheap.

Go to http://www.karnatik.com/shrutibox.shtml

Copy sound files at the pitches you want (all 12 ET semitones are available, 1 min or 8 min).

Put them on an MP3 player or copy them onto CD (which is what I did, with iTunes) and you've got a shruti box that fits in your pocket for next to nothing.