Icon Tutorial-3 ways to do Background Text in Photoshop
These are for photoshop,I use a very old (CS2,lol) version but it should work for any version.Perhaps GIMP too but I'll have to try that out before I can say it with surety.
Concrit is welcome and please ask any questions if you have. :D
1. BG text using polygonal lasso tool or eraser.

( Polygonal lasso / Eraser )
2.Using the Eraser to erase the background and add text behind.

( Eraser tool tutorial )
3. Using the Pen tool and clipping mask

( Only a few steps )