This works best with a large font on a large canvas. Unless otherwise specified filters are run at default values. Because the colour to alpha filter (used in step 3) is not currently available in the windows version of gimp (as of version 1.2) and I can't think of a workaround this is probably only of use to linux users, also drag & drop (step 3a) isn't functional on windows version so a colour would have to be set manually.
map=''text layer''
azimith=0
depth=22
The bumpmap layer should now look like this;
script-fu > shadow > xach effect
blur=8
Thats the base all done and ready and should look like the image above, waiting for you to add your own touches.
Turn off the bumpmap layer, reduce opacity on shadow layer to about 20, merge both shadow and highlight layers, then run filter > enhance > unsharpmask on merged layer.