First of all I suggest you to read the following FAQ:
How to get the URL of a media stream

I also suggest you to try WM Recorder and Replay Media Catcher. Both have demo versions that can be used to find stream URLs:

WM Recorder in AUTO recording mode can automatically record Real Audio/Real Video/Real Media, Windows Media and Flash HTTP .FLV videos. In demo mode you may only record a couple of minutes with it, but you may easily get stream URLs for free.

Replay Media Catcher can record HTTP and RTMP .FLV flash videos. It finds flash stream URLs and automatically records them. And it is the only RTMP .FLV stream recorder released so far.