EDIT: ADDED HORIZONTAL AND DIAGONAL NEVER ENDING TEXT LOOPING
ON MAY 1, 2013!
PHOTOSHOP TUTORIAL: SIMPLE TEXT ANIMATIONS
Hello and thank you for reading this simple tutorial i made. This tutorial is about creating simple text animations mostly used in avatars and signatures. Creating GIF files needed ADOBE PHOTOSHOP CS3 or above.
To start with, open your photoshop, choose Window->Animation to show the animation/frame window. An Animation window will pop out from the bottom part of the work area.
Otaku-Streamer's Forum Background
Avatar Background Color - 1B1B1B
Content/Signature background Color - 161616
*Thank you for "Sin Of Love" for telling me this when i'm learning Photoshop back then.*
*Thank you for "Enma Ai" for telling me about the on-screen keyboard, because my laptop doesn't have a printscreen button.*
*Thank you for "Ragnarok" because i was inspired to learn Photoshop from him after i joined OS community.*
INTRODUCTION
If you're new to creating GIF files in photoshop, here's a brief information about some important parts of it.
Frames - It's the boxed version of your whole work area, and on the upper left corner of it show the frame number. You could drag any frames to adjust your animation.
*Frame 1 is like the master frame, doing anything on the layers of frame 1 would also affect the rest of the frames. To make it easier, make frame 1 the starting animation of your GIF.*
Delay Rate - It's the number below the frames. 0 sec is the default speed for your frame to frame animation. You will adjust the speed of each frames accordingly to your liking. It determines the number of seconds or mili-seconds before switching onto the other frame when you play the animation.
Looping - Ok, this is the command that let's you choose how many times the animation frames would continue to animate, default is Forever, which means if you start the animation, and it reaches the last frame, the animation would repeat from frame 1, and so on. It's located Below the frame 1 box in the animation window.
Delete Frame - It's the icon of a garbage dump. Like what it name implies, it deletes the selected frame/s.
Duplicate Frame - It's the icon on the left side of Delete Frame. It duplicates the selected frame/s. this command can be abused because it can duplicate any frames, making animation easier.

Now That's done, let's go into our first simple text animation!
NOTE: I'll be using a 180x300 pixels size, which is the current limit to OS avatars.
And a "1b1b1b" background color.
VANISHING TEXT
This one's is on the list of easiest text animations, it only needs 1 Text Layer, and that is it! You just adjust the Opacity of the text on each frames!

1. Let's start from frame one, with 100% opacity on the text layer.
2. Click the duplicate frame icon, and it creates a copy of layer 1.
3. Select frame 2 (The copy of frame 1), go to the Layer panel and change the opacity to 75%. It makes the layer slowly vanishing. The lower the opacity, the harder the effect.
4. Duplicate any frame, but for this, let's duplicate frame 2.
5. Select frame 3 (The copy of frame 2), change it's opacity to 50%.
As you notice, i gradually lowers the opacity by 25% each frame. continue this pattern until 0%. Now try playing the animation by pressing the play button at the animation window! Is it too fast? Adjust the delay rate of each frames, example would be 0.1sec on each frame. If you want a pause before and after the vanishing part, select frame 1 and adjust it's delay rate to 2sec at the 5th frame, set the delay rate at 1sec. You could experiment many outcomes if you're willing :P
We have 5 frames in this vanishing text.
frame 1: 2sec delay
frame 2-4: 0.1sec delay
frame 5: 1sec delay
Looping: Forever

YOU COULD CREATE A BLINKING TEXT FROM VANISHING, EXPERIMENT AND YOU'LL FIND MANY OUTCOMES.
To save your GIF file, Go to File->Save for Web&Devices..