pcapsipdump is libpcap-based SIP sniffer with per-call sorting capabilities. It writes SIP/RTP sessions to disk in a same format, as "tcpdump -w", but one file per SIP session (even if there is thousands of concurrent SIP sessions).
This is an excellent product. It fills a niche that is very much needed. the new (in 0.2) -R option is great.
Extremely useful tool. Thanks.