This is a quickie that I got the idea for from CoolType.

Start with some text and make a duplicate	I used a 80pt bauhaus in a 250x100RGB with antialias 3	c-N c-T a-D
Gaussian-Blur the duplicate and Offset with the same amount as you blurred, then Invert it.	I used 3.0 but you might need more for a bigger picture	s+a-B a-O a-I
Now empty the U-2 canvas and bucket fill it with 50% grey. Then Multiply U-1 and the now grey U-2.	You have to use the grey canvas and multiply if you used antialias, otherwise there will be a whiteish border...	c-K s-B a-M
Now you run a Difference on U-2 and U-3 and you get what's to the right.		s-a-D
Now play around with the gamma settings.	Try doing a Relief on this canvas (a-R)	Map/ BCG
Here i Scaled (20pix in all directions) a bluish version, Blurred by 3.0 and Inverted. Then I ran a Difference between this and the previous.	I also used a Contrast Autostretch on this to shrink it down.
Do the same as above but do not Invert the Blurred image before running the Difference. But Invert it afterwards and you get this.	This is perhaps the best one IMHO.