Free FLV Converter can download and convert Internet videos. The program supports searching on multiple video sites directly from its interface; then you can preview the clips and pick those you wish to download. Unfortunately, I did not find any kind of integration with browsers to monitor downloadable contents; however, you can enter single URLs or even several video URLs directly from a text file. What is more, you can keep the original format of the downloaded videos, but also automatically convert them to other formats if you wish.
Not only can downloaded clips be converted, but also any other video file from your local disks. The program specializes in converting in two directions: from FLV to other formats and from other formats to FLV. A wide range of formats is supported and some of presets are described with the names of the supporting devices to prevent compatibility issues. However, if none of the presets meets your exact needs, you can always configure such parameters as codec, bitrate, frame rate and audio codec. Unfortunately, I could not find some popular codecs like Xvid there.
In general, Free FLV Converter has a nice and intuitive interface supporting various languages. It has the main advantage of combining downloading and converting in a single application. In addition, the program can check for new releases automatically, so that you can always use the latest version.