NOTE, just FYI, I moved this thread to Dynamics and Effects for all to see, as it belongs here in this forum

Ok, this is one of my favorite shots in the mummy series, apart from anything with the Scarab beetles!

There are 2 main ways you can make this happen,

1. (quick and dirty & not very realistic)
Make your text, and use it as a goal for LOTS of particles and/or particle objects, then render out that simulation, and in your post app, just reverse the frames to give you the particle animation you need.

2. (the way I would do it, i.e the long way)

a. Model, and texture your text objects till you are happy with the look.
-NOTE: For the sake of speeding up calculations, it might make sense to convert your text to polys once you are happy with the look of them, combine, and then texture it all as a whole...
..personal preference I guess

b. For fun, add a few bits of softbody strips (nurbs) to the text for that "mummy" feel.
-Remember to tweak/paint the weightmap so they will "blow" along with your particles via any dynamic fields you will add to the shot.

c. Now, hide everything BUT your text object(s).

d. Make it a surface emitter with LOTS of particles, OR make full copies of the emitters.

e. Adjust the attenuation so that the particles are born, and appear to "stick to where they were born on your text object(s).

f. Once your text objects are covered with your particles to your liking, hit stop, and make that frame for your particles "Initial State".
(see docs for usage on setting Initial State for Selected)

g. Add fields, and animate/tweak to taste


TIPS:
Obviously, use many particle objects with varying colors and densities to achive clumps and some extra depth.
Plus, using more particle objects, allows you to render in passes, giving you ultimate control over look and timing.