I use a slightly different method than one described at the Letterhead fonts page to create prismatic effects in letters. It's a little more complicated, but works well on curved letters.
In CorelDRAW, I use the blend function to create the center line on the letter. First I break open the paths of a letter, such as "C" for example. I use a 1 step blend between the outer curve and inner curve on the "C". At first the blend will be messed up, but if you select one of the two control paths of the blend and click the Reverse Path Direction button it will create a uniform center line from one end of the "C" to the other. From there you use your subjective judgment on how to trim the center line and create the prismatic bevels.
Some blends have to be created in smaller chunks. The process can get time consuming if you're working with complicated letters. But the end result looks far more controlled and deliberate than the horrible looking prismatic bevels so many people crank out of Photoshop. Computers just don't know at all how to create a prismatic bevel effect properly with any sort of 1 click filter.