Finding code clones in the open source systems is important for efficient and safe reuse of existing open source software. In this paper, we propose a novel search model, open code clone search, to explore code clones in open source repositories on the Internet. Based on this search model, we have designed and implemented a prototype system named OpenCCFinder. This system takes a query code fragment as its input, and returns the code fragments containing the code clones with the query. It utilizes publicly available code search engines as external resources. Using OpenCCFinder, we have conducted several case studies for Java code. These case studies show the applicability of our system.