A client gave me a logo in jpg, bitmap and tif formats. It has a white background. He wants me to be able to drop it into an ai flyer that has a multicolored background and does not want it to be on a white backdrop - just wants the logo without that pesty white behind it. I have been messing with this for HOURS and cannot seem to make this happen. No, I do not have the original psd or ai files.
This is what I have been able to do:
-Select and carry alllllll the elements of the logo into new psd docs with Transparent backgrounds.
-Take those elements, now onTransparent backgrounds, and put them together into one new psd doc.

This is where it gets messy......while I would have thought that would have done the trick, when I SAVE the new logo with the Transparent background - and regardless of what format I save it into....jpg, tif, etc. - I STILL end up with a logo with a WHITE background.
This is maddening. I bet it is quite elementary for people who know the programs well. Hope so!

Save your work as a .psd. It will have the layers and transparency information stored in it, while .tiff and .jpg don't. Then go to Illustrator and use File->Place to use that file in your .ai file.

(You are creating a reference to the original .psd file, so remember that a copy of the .psd file needs to travel with the .ai file, and any changes you make to it will be reflected in the .ai file.)