need help saving an image without a white background

I created a logo in photoshop. It has no background. When I save the logo in another format for use in other programs it saves a square white background. This is bad when i want to paste the logo ontop of an image. How do i save the logo without the white background?

It depends on what you are going to do with the image.

For web purposes save the image as a .gif or .png both of which support transparency.

For introduction into programs like Quark, In-Design or (heaven forbid) Pagemaker. You can use the .eps format and apply a clipping path.

In newer versions of Quark and InDesign you can actually import the native .psd format and they both support the transparency of the file.

i want to insert the logo into my email signature, my ms word leterhead, and my web page, all of which have different color backgrounds.

Your email sig and web page will best beserved by using the .gif or .png formats. Because they have different BG colors you'll most likely have to save a version for each using "Save for Web" and in the field where it says "matte" you'll need to select a color that matches the BG in each.

I don't really use MS word so I don't know what image types it will import. If it will place an .eps graphic that would be the format I would use.