Fortunately it is ot too difficult to add this piece of behaviour. The following code is applicable to an instance of the FLVPlayback component on stage (instance name 'player') not using a skin but using a custom UI seekbar component (instance name 'seekbar').
seekb.addEventListener( MouseEvent.MOUSE_DOWN, onclick);
seekb.useHandCursor = true;
seekb.buttonMode = true;
function onclick(e:MouseEvent):void
{
var seekto = ((this.mouseX-seekb.x)/seekb.width)*100;
trace(seekto);
player.playheadPercentage = seekto;
}
Give that a try and you should be able to click the seekbar to jump to any point in the video (provided you are streaming or - if using progressive download - the video has already loaded up to the part you are trying to seek to).


Feel free to file this as an enhancement request if you think we should add it to the UI.
- brad