Some of my trainees are surprised to find that they can apply many transformations to text in Photoshop without having to rasterize the layer. You can Scale, Rotate, Skew, Warp, Flip Horizontal and Vertical and STILL go back and edit your type without any problems.
To apply transformations, make sure the Text layer is selected in the layers palette and then choose Edit > Transform. From there you can choose from all of the transformations listed above.
After you’ve made the transformation, you can edit the text again if necessary. Just select the type tool and click on the type you want to change.
If you want to use Distort or Perspective transformations, however, you will need to rasterize the layer first. Rasterizing means that you are converting vectors to a bitmapped (made up of pixels) image. To rasterise text, choose Layer > Rasterize > Type. Once the text is rasterized you can transform to your heart’s content.