I don't know about how they would hang on your bike, but Jaand folding grocery baskets are great. Look at http://performancebike.com or http://bikenashbar.com
Also my LBS sells panniers that are connected and drape over the back rack--very convenient.
Or: check out http://cobbworks.com and look at their Oyster Buckets
I just searched and found this link to a recumbent basket idea:
http://www.humboldt1.com/~mhp/rubbermaid.htm
and here's another one: http://www.ihpva.org/pipermail/workb...q3/000633.html
These links may lead to yet more links. I've spent hours doing that many times looking for basket advice.