One Way Network Sniffer (OWNS) can be run on Windows and Linux. It can open pcap files for extracting images, videos, http files, emails... It can be downloaded from (SourceForge ).
Other interesting tools that can open pcap files are IMSniffer, for saving IM conversations (Live Messenger, Yahoo!, AIM, ICQ,...), MSN Webcam Recorder for saving MSN webcam streams, and Yahoo Webcam Recorder, a Java app that saves Yahoo Webcam Streams (sorry, no link).
Don't forget popular Cain&Abel. It can be used for voice calls.
There are a lot more options in the Linux world ;-)
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EPSILON