SEG-Y files need special compression because they don't compress well using gzip and the like. The code is cross-platform C++ using nothing else than standard system libraries. This is a spin-off from the OpendTect project (http://opendtect.org).
MessageReader is a java software that, given a Mail folder of a Symbian phone, takes all the sms messages (NOT (still) mms or anything else) and make a file in the unix mailbox format (suitable for e.g. kmail).
Java program to extract postings and comments from http://www.livejournal.com (blog) into DB and view/classify/process it. LJ loader. Components to reuse: perl-like, but efficient Web pages scraper, trees analyzer, concurrent scheduler.