Some online conversion sites can download FLV video, such as Zamzar, Keepvid,etc.
Or you can use the Free YouTube Downloader tool to download FLV videos.
Yahoo search for you:
How to get youtube videos (flv) for free
Why don’t you search in google because google has a capability to search anything you want with less effort. You can also use other search engine like yahoo and other kind of search engine.
Try leawo Youtube download, it’s totally free.