Here are three extensions for the Blog engine.net

1. Mp3 Player :

[mp3:Ring_AlaiPayude--Jalatharangam.mp3]

2. Flv Player :

[flv:sivamani.flv] 

3.Snap Shot 

This will show the snap shot of the external links 

Here is the details of the extensions

Mp3 Player this from rtur.net

Flv Player  from Betaparticle

SnapShot from ThinkEdge

But when i tried it with opera it was not working, not sure if it is something wrong with my Opera settings.

I just inserted one Embed tag inside the object tag and it is working fine in all browsers 

here is the edited flvplayer.cs (4.74 kb) which solved the issue

for mp3 player  it is here mp3player.cs (9.04 kb)