Logos with the text reflected below them are one of the popular "Web 2.0" styles, and they're very simple to create in Photoshop. This short tutorial will show you how to create a logo like this one:
There are plenty of similar tutorials out there on the web, but I couldn't find one that creates a logo that looks good on top of a textured or gradient background. This one work since it's background layer is transparent.
First of all, go into Photoshop's preferences and change your transparency grid colour to "dark". This will allow you to see your translucent white text more easily.
Next, create a new image with a transparent background. I played around with the image size a few times to find a size that would be right for my logo.
Now choose the text tool, with the "horizontal type" option.
Use the text tool to enter the text for your logo.
Create a new layer. This will be a transparent layer over the top of the existing one.
Now choose the text tool, with the "horizontal outline mask" option.
Enter the same text again, in exactly the same size, then use the gradient fill tool to fill the text with a gradient that goes from white to transparent.
From the Edit menu, choose Transform and Flip Vertical.
This will flip your text to make it look like a mirror of the text in the first layer:
Save your image as a PNG file, and make up a web page with a coloured background to test it with. Here is the result I got by following these steps: