Basically it's not an option, but if you want to mod the source so they dont autoplay the lines that need to be changed are in mediamodule.ascx.vb file.  About line 62 in the constants region.  Make the changes in bold.  and then recompile the dll.

Private Const WinMediaTag As String = "<embed src='{0}' {1} {2} {3} autostart='false' pluginspage='http://download.microsoft.com/download/winmediaplayer/nsplugin/6.4/WIN98/EN-US/wmpplugin.exe' type='application/x-mplayer2'>"

Private Const QuickTimeTag As String = "<object classid='clsid:02BF25D5-8C17-4B23-BC80-D3488ABDDC6B' codebase='http://www.apple.com/qtactivex/qtplugin.cab' {2} {3}><param name='src' value='{0}'><param name='autoplay' value='false'><param name='controller' value='true'><param name='loop' value='false'><param name='type' value='video/quicktime' ><param name='target' value='myself' ><embed {2} {3} pluginspage='http://www.apple.com/quicktime/download/' src='{0}' type='video/quicktime' autoplay=false controller=true loop=false target='myself'></object>"

Private Const RealMediaTag As String = "<OBJECT CLASSID='clsid:CFCDAA03-8BE4-11cf-B84B-0020AFBBCCFA' {2} {3}><PARAM NAME='SRC' VALUE='{0}'><PARAM NAME='CONTROLS' VALUE='ImageWindow'><PARAM NAME='CONSOLE' VALUE='one'><PARAM NAME='AUTOSTART' VALUE='false'><EMBED SRC='{0}' {2} {3} NOJAVA=true CONTROLS=ImageWindow CONSOLE=one AUTOSTART=false></OBJECT>"

best wishes,

bentangle