The Chopra Center offers, from time to time, a session with 21 meditations to be done in 21 days. It is free and you can register at their website and receive the downloads of sound and sometimes visual with it through your email.
If you want to check it out, try the link http://www.chopracentermeditation.com/bestsellers/MEDITATION_WINTER_2012/register.asp
This session is during the winter in 2012, from February 20 and continuing for 21 days after that. I divided this 21-day experience into three parts, each one talking about 7 days and how the meditations presented have affected me, and hopefully other friends of mine, who are also participating in this 21-day challenge. If you want to leave your impresson from your own experience, just submit a comment or email me your text and I can post it here.