Recursively search for files contained in jar/zip files.
This isn't for searching inside the files, like zgrep, but for matching the file names themselves. For instance:
$ zfind org.apache.http.client.params.HttpClientParams ~/.m2
will search Maven's local cache for any jars containing the HttpClientParams class. It turns out the dots in the package name conveniently match slashes in the java class's name:
Ah, there it is!