Wood Grain
Create a new 250 x188 @ 72 dpi graphic and type the letter 'O' in 225 point Arial Black.

Create a new layer and fill it in with white. Filter>Add Noise. Use the following settings: Amount: 72.09; Gaussian; Monochromatic.

Let's begin to form the base for our grain by going to Filter>Blur>Motion Blur with the following settings: Angle: 0; Distance: 30.

Now we have to make the straight lines wavy. Go to Filters>Distort>Wave using these settings: #Generators: 6; Wavelength Min.: 1; Wavelength Max.: 120; Amplitude 5/35; Scale Hor.: 89; Scale Ver.: 7; Sine; Repeat Edge Pixels. The scale needs to be low so that the waves aren't too overdone.

We then bring out the depth of the wood with Filter>Sharpen>Unsharp Mask using the settings: Amount: 500%; Radius: 2.9; Threshold: 0.

Now lets add some color to the wood. Image>Adjustments>Hue/Saturation with the following: Colorize; Hue: 22; Saturation: 53; Lightness: -19.

To break up the uniform look of the wood, we will now create a little variation in the grain. Select a small area of the wood and then Select>Feather with the amount set to 10.

Apply the wave filter again with the following modifications: : #Generators: 59; Wavelength Min.: 1; Wavelength Max.: 120; Amplitude 5/35; Scale Hor.: 89; Scale Ver.: 7; Sine; Wrap Around. Select another section of the wood area and repeat (Ctrl+F).

While holding the "Ctrl" button down, click on your original text layer. This will select the outline of you text. Then Select>Inverse and press "Delete".

Add some depth to the letter: Layer>Layer Styles>Drop Shadow and use these settings: Mode: Multiply; Opacity: 100%; Angle: 120; Distance: 3; Spread: 0; Size: 5