With NWBC you can search for entries within the navigation tree using a type-ahead input field. Type in a query string in the quick launch and all matches in all roles are displayed. Transactions or WDA applications available in the WebAS backend can be started directly.
You can also add your favorite OpenSearch provider (see http://www.opensearch.org), e.g. wikipedia, disable search providers and configure the order in which they appear in the dropdown menu of the quick launch.
More Information see SAP NetWeaver Business Client End User Guide -> Quick Launch