You could try video and post it on YouTube. Lots of developers are doing this so it's not like you'd be the only one. You can also make it private or just not public so that you have to specifically go to the youtube link to access it so that only those interested in the video would see it.

If you do want to do a particle engine using SDL's graphics I'd recommend staying away from any alpha, rotation or scaling. Basically anything that makes a particle engine do what it does. You could use only pixels and alter the color of them from it's base color to the background color of your screen to give the illusion of fading out. You then will have to sort your particles drawing order by life remaining to prevent the majority of a distorted effect. That's considering you are just using a single background color, which might not be the case. Still, OpenGL or D3D are your best bets. OpenGL is my personal favorite so I would of course recommend it, especially since SDL games and programs are more easily adapted to use OpenGL instead of DirectX. (You can keep using your existing window management, input and audio code for example.)

For OpenGL you are best to go to the NeHe website at http://nehe.gamedev.net/ their tutorials are awesome.