Start with a new RGB image. Type some text using type tool. Note, if you are using Photoshop 4.0 it will create a layer of your type. You must merge it down if you want this trick to work. Just hit Ctrl-E (Cmd-E on Mac). In the Channel Palette (Window>Show Channels) drag any of the channels to a new channel icon.
Now, switch to channel #4 and click that right arrow button in the top right corner of the channel palette and choose Duplicate Channel...
Go to Channel #4 copy and Filter /Blur /Gaussian Blur /3.0
Filter /Stylize /Find Edges
Select /Load Selection/#4 Edit /Copy Now switch to the RGB channel, select all and fill it with color (white for example) Edit/Paste
Now the good idea would be to colorize it (using Image >Adjust >Hue /Saturation...) and drop a shadow.