Ok this was ma first tut......
make a new document or just get ur sig and for text ive just put a 1..

1.goto ur gradient tool and select the star gradient make it small by dragging the tool just a wee bit not too long...
2. switch to image rdy...
3. make new layers and each layer move the gradient star along down the text every new layer

once uve went through the whole text u should get somethin that looks like this