Now we need to make the images transparent. In the Warps and Filters palette, click on Wash. Make sure the Wash Opacity slider is still at 50%. Select one of your images and click Apply. Repeat for the other image.
Render a square/rectangle, in the same color now in the Current Color Swatch, a little larger than your largest image. Right click it, select Send to Back. Center all three images. Flatten (Ctrl + F) all three. Crop as needed.
Your image should now look like this:
Now simply add the text of your choice and your're done. And like I always say, do the happy dance! Remember though, photos with text on them render poorly as a JPEG. This next image, I saved as a GIF after optimizing the color palette. The above image, sans text, was saved as a JPEG.
There are many variations that can be done along the way; using different colors, using only part of an image, creating a "blurred edge" image to start with - the variations are limitless. Hope this has given you some ideas.