I like to check for ways to make/purchase recycling yarns and the tutorial on how to make yarn from t-shirts fits perfectly.
At my next jumble sale visit I really have to look what they have as T-shirts.
Links:
T-Shirt Yarn
Here at unikatissima:
Handspun Newspaper Yarn
Recycled Yarns
Coloured Yarns
Plastic Bag Tote