FLV Player allows Flash developers to playback .flv files without the need to load them from a server. Just select the file or drag/drop it onto the player to view it. Standard playback controls included. The program can be optionally associated with .flv files, so you can just double-click them to play. It is able to play On2 VP6 encoded FLV files and include a resizable window and zoom 1x/2x buttons to allow for quick jumping to the FLV's original size (after resizing FLV Player's window, for example) and to look at your .flv file at 200% zoom.

It also supports loading an FLV file or stream from either a regular webserver of an RTMP streaming server. FLV Player is based on Flash Player 8 and utilizes the default Macromedia FLV Playback component, which uses a slightly customized skin (blue instead of green highlights). FLV Player is built with Screenweaver Open Source, which is still in beta, so your mileage may vary.