Google Base
http://base.google.com/

Caspio Bridge
http://www.caspio.com/

Dabble DB
http://www.dabbledb.com/

eUnifyDB
http://www.eUnifyDB.net/

Lazybase
http://www.lazybase.com/

MyOwnDB
http://www.myowndb.com/

QuickBase
http://www.quickbase.com/

Trackvia
http://www.trackvia.com/

Zoho Creator
http://www.zohocreator.com/