How you do it, depends on if you have white in your foreground image. Generally using the blend modes is the quickest. The main three to remember is multiply, screen and overlay. Try them out on your image and see what happens. Make sure you have another layer below your image so you can see whats happening.
When you say 'color keyer' are you talking about video or a still image?
I'm a video guy, so I'm thinking keyer. I used the magic wand to select and inverted the mask. Not sure if that's the proper way to do it. What I'd like to know is how to change opacity of a selection. Say if I didn't want to remove the background entirely. Or apply a gradient. I am not too familiar with Photoshop and I am not finding the answers easily in the help files.
Blend modes will work with video. The closest thing to color keying in photoshop is Select > Color Range. Use the select drop down and select highlights.
Peroplus, you said you are a video guy, but have still not said if it is video you are working on. If it is a still image, then are numerous ways to make the selection. Logos thend to be graphic in nature, and respond well to being selected with the Pen tool. Otherwise, the best method will depend on what version of Photoshop you are using. If CS5 or later, then the Quick Selection tool followed by the Refine Edge takes some beating in lots of situations.
But if you want a decent meaningful answer, for goodness sake give more information
Video or still?
Version of Photoshop?
Do you want a transparent background, and what is your end use of the resulting graphic?
Upload an image of the Logo.
Here is the image. It is a logo for a company. I am trying to incorporate it into a lower thirds title in Premiere. I was able to get rid of the white using the magic wand and deleting its inverted mask.
I also want to animte it - make it 'fly' away. What is the best way to do that? In After Effects or what other program in CS6?