I had a need for some extra wire cube connectors similar to:
http://www.organizeit.com/wire-cube-plastic-connectors.asp?cmpid=gpa&gclid=CKP_gMfQt7cCFeZxQgodUWwA9g

For wire cratres like:
http://www.bedbathandbeyond.com/product.asp?sku=16719773

This design is only a 4-way (rather than the 8-way linked above), and does not allow connecting a top or bottom (which I didn't need)