There are several programs like :
URL Snooper
Code:
http://www.donationcoder.com/Software/Mouser/urlsnooper/downloads/URLSnooperSetup.exe
URL Snooper is simplier to use but sometimes it can't sniff the whole rtmp stream source. That's why when URL Snooper locates rtmp stream, rtmpdumphelper is required for more informations concering this kind of streams.
Wireshark
Code:
http://www.wireshark.org/download.html
Wireshark is more powerful but you have to learn key words how to filter stream addresses in order to locate HTTP or RTMP source.