Flash video format (.flv) is so popular in thee web, from Youtube to many other video portals. Here is a list of free programs you can use to download and convert them.
Free FLV Converter llightweight and easy to use. It allows to download videos from over 500 web sites and convert them in various formats; it supports AVI, MP4, WMV, WMA and many more.
During installation you can choose a custom setup so you can skip to install an ad-aware.
Once started choose language (many supported), you can directly search video from the program, or if you already have the link you can paste the URL using the “Download Video” tab.
Once you have downloaded the video in .flv format you just need to go in “Convert from flv” tab, open the file and choose the output format for the conversion.
Orbit Downloader similar program (even if this is specifically for download) with interesting features like WebM and HTML5 video support, it supports RTMP / MMS / RTSP streaming protocols, it supports IE, Firefox, Maxthon, Opera.
StreamTransport this useful program allows to download videos also in the sites where other programs doesn’t work. It supports many streaming protocols, it has features to automatic detect and capture videos from URL.
TubeMaster++ written in Java (so it requires JRE installed), download available for Windows, Linux and Mac, work both on 32 and 64 bit systems. It also require capture driver/software installed (JPcap in Linux and Mac, WinPcap in Windows, both free).
Important features are the conversion in other multimedia formats (AVI,MPEG,MP3,MP4,WAV,WMA,MOV etc…), a built in search engine to find videos and mp3.
RTMPDumpHelper Nirsoft utility that uses RTMPDump Toolkit and allows to capture RTMP video streams