Ironicly, there is a paintFX brush that does exactly this automaticly

Just draw a curve on the surface you want the blood to appear on, attach the brush to the stroke, and play back/render the sequence, and the blood will drip-down the surface.
Just animate the near/far clipping values of the brush to get it to "splatter" onto the wall/surface before the dripping begins

Otherwise what bending said about the blobby particle render-type is correct.

Another thing I would suggest, if you are familiar with a compositing package, you could always do it in post.

Bend and warp real splatter footage onto the surface you require.

Also, it really depends on the style of blood you require.

B-movie gore blood, simple splatter, long streams, etc.