KSniffer
NaLug has its "famous" developer! Our LUG-ian (allow me this term) Slacky has developet a QT/KDELibs-based sniffer, published on the KDE official web site. Here the direct link:
KSniffer
KSniffer captures the packets on every interface that is in state "up". It handles TCP, UDP, IP, ICMP and ARP protocols; moreover it saves the dump in libpcap format, so that it's fully compatible with Tcpdump and Ethereal. For more informations, read the ChangeLog inside the tarball.
Great work Slacky, go on!