It's very easy to create 3D text effect with Photoshop (even if you don't have Photoshop CS extended to do it).
Check out my easy 5 easy steps!
Open a new document with the size of : 800px wdith x 400px height. Color the background to black. Next, make a another layer, right on top of it and use the brush tool (with light pinkish color) above the background color.
Create the alphabet "a" by selecting the "Horizontal Type Tool". Next select the "Layer Style". On the window popup, select the "Gradient Overlay" and create gradient just like above. Once done, click OK.
It's time to create the 3D effect (thickness). Select the "a" layer, hold down the alt key on the keyboard and press the down arrow key then the left arrow key (keeping alt key pressed down) do this about 10-15 times, this will determine the thickness of the alphabet. Now select all the thickness layer(except the "a" layer") then press "ctrl-e" to merge it all.
Move the layer below the alphabet "a" and click on the layer style.
Choose the "Gradient Layer" and color it to darker shades just like above image. After that, select "drop shadow" and set it according to your preference.
You're done! :)
Note : For other alphabets, use the exact same process, but for the step 3, try use the other arrows to create the depth. ie. right arrow and top arrow etc.
You can also create effects for the background. I've used the brushes from "Sparkling Effects" to create the effects for this. You might want to try it as well.
Here's the PSD file ("http://www.ramesstudio.com/adobetuts/3D_typo.zip)" for this tutorial, together with the fonts.
Hope you find this tutorial useful.