Pattern Effect

1) Very simple open a new
document get a logo, pic, etc..
here I am using the letter O,
I rasterize layer.

2) Grab the Rectangular Marquee
Tool (M)
select around the letter
O like in the image on the left
and crop it (Image --> Crop)
Now go to Edit --> Define Pattern
and name it o apply.
3) Open whatever sized Document,
Grab the Paint bucket Tool (G) change the fill from Foreground to Pattern in Pattern option next to it select the O image you made. Go to your
document on a new layer drop
the Paint Bucket! Thats it :)