Uploading FLV is not more then progressive download or download first and see
it after.

Use of FMS will do real streaming ... i.e. frames of movie will get downloaded
and also get played ... so you can enjoy 10mins clip in 10mins and few seconds
more if you are viewing correct encoded version of movie and you have good
internet connection... without FMS, it will first download 10mins of clip and
then display it to you.