I give individual clarinet lessons to a large number of students and i am continually looking for new material and methods in order to give them the best and most interesting experiences.
If you go into a music store, you'll notice that there are a great deal of 'playalong' cds included with books at the moment - although playing with a cd isn't what i would call learning to be a musician.

Why?
I come across a lot of students who can't *read* music. When it comes down to it, learning to read music notation correctly can give you the most enjoyment in the long term. Sure, it might be hard work - but if you ever want to play in an ensemble it will be very useful. It also opens up a whole new world of music available to play.

That said, technology certainly has its place and the cd's are really very useful in the situation where i can teach the student *how* to use them for maximum benefit. If you haven't got a teacher - get one! But then i would say that wouldn't I?

As some other posters have mentioned, the ability to record is brilliant. I take my notebook to all lessons and where appropriate i'll record my students playing and let them critique their own performance. Being a musician is as much about listening as playing. This also means I can collate their best performances over a longer period and burn a cd for them to take away.

I'm also working with a company in Australia who are developing instrumental teaching software and it is taking some old ideas to new levels. The cd playalong concept is at work here, although now we are in front of an everyday pc seeing music notation, hearing a band, orchestra or piano accompanist and actually playing inside the ensemble. On top of that, the software is calibrated to listen to your playing and let you know how well every note is played. Are you in time? Is your intonation good? Feedback that is genuinely useful to a musician of any level.

Just in case you didn't see it the first time - I work for this company, so make what you will of it. Or you could just try it out for yourself: http://inthechair.com

Oh, and to the poster that was advocating the quantity for quality technique. I'm wary of playing for long periods of time purely for the sake of doing lots of practice. If you are going to be the best you need to learn how to do the most practice in the leanest time. Playing for hours on end is sometimes fun, usually painful and often plain stupid.