Web-sites with streamable Flash video and audio (.FLV and .MP3). Mostly free.

The most popular web-sites with Flash videos (RTMP and HTTP):
Google Video (HTTP flash video)
Youtube (HTTP flash video)
iFilm (video)
Blip.tv (video)
EOnline (RTMP flash video)
FabChannel (RTMP flash video)
video.freevideoblog.com (flash video)
Metacafe (flash video)
music.vidnet.com (flash video)
ABC (RTMP flash video)
NBC (RTMP flash video)
New York Times (RTMP flash video)
Reuters (RTMP flash video)
TVGuide (RTMP flash video)
MusicBox (RTMP flash video)

The most popular web-sites with MP3 audio played by Flash player (RTMP protocol):
MySpace (RTMP and HTTP MP3 audio)
Pandora (RTMP MP3 audio)
Radio Blog Club (RTMP MP3 audio)
Wolfgang's Vault (RTMP MP3 audio)

Other web-sites with Flash videos (RTMP and HTTP):
6room.com (Chinese simplified)
angryalien.com
ArtistDirect
Blastro
Blennus
BravoTV
Bofunk
Bolt
Break.com
Castpost
Current.tv
devilducky.com
findvideos.com
grinvi.com
grouper.com
hiphopdeal.com
lulu.tv
midis.biz
music.com
musicvideocodes.info
myspacevideocode.com
newgrounds.com
pcplanets.com
pixparty.com
revver.com
sharkle.com
videos.streetfire.net
thatvideosite.com
theonenetwork.com
Tudou.com(Chinese simplified)
videocodes4u.com
videocodesworld.com
videocodezone.com
vidilife.com
vimeo.com
vsocial.com
web62.com
zippyvideos.com

How to record and play Flash video streaming
FAQ: How to record/download/capture/save Macromedia Flash .FLV video HTTP stream from embedded player
FAQ: How to record/download/capture/save Macromedia Flash .FLV video RTMP, RTMPT stream from embedded player
FAQ: How to play flash video files