PLIST Editor is a side-by-side tree & text editor for property list (plist) data. In a clean and easy to use interface, it allows you to quickly create, inspect, modify and save your .plist documents.
Quick Plist Editor contains a very useful Visual Tree Plist View that allows you to quickly look at the structure and hierarchy of a plist file and directly modify the property name, type and value of each node.
Xplist -- Open source cross-platform lightweight plist file editor This is a lightweight plist editor with rich features. The file format supports XML and binary plist files under all platforms.