My friend Amy gave me my first yoga mat.
I bought my first one at Gaiam, as part of a kit that included a strap and two blocks.
In fact I've trashed a lot of mats, and don't know what to do with them.
At Dharma's they cut them into strips, tie them, and use them as elastic rings to help people bind in poses such as full pigeon.
But now there are 50 ways to re-use your old mat listed on the Gaiam website.
My favorites include:
-Donate to homeless shelter
-Use in place of packing peanuts
-Pet carrier liner
-Soundproofing for garage bands
But there's so much more than what they've listed.