**NOTE: May work with other programs. I have not tested it, but this is mainly for Photoshop**
step 1:
type your text. this may work better/be more noticeable with a bolder font
step 2:
go to layers>new layer>hit "ok"
step 3:
go to the gradients tool and choose a gradient. place it across your layer
step 4:
press CTRL-G
step 5;
save it[:
Depending on the gradient you used, it should look something like the one in my signature.
Enjoy!