Bitmap question: Can I turn the white background transparent?

I have a black and white bitmap. I'd like to have the white background become a transparent background. Is there a way to do this? I started out with a full color RGB file, turned it grayscale, and then changed the mode to a bitmap....but of course ended up with a solid white background around the black pixels.

So, I'd like to keep the black pixels and ditch the white background.

Thanks.

Tom

Bitmap mode won't offer transparency. You'd have to convert back to grayscale to achieve that.

Funny thing....I placed the bitmap into Illustrator....which comes in with the "white" background totally transparent. I then selected the bitmap and gave it a "fill" color. Then I copied it and pasted it into Photoshop...and voila....no white background in photoshop anymore. (giving it a fill in AI had nothing to do with the transparency of course...just wanted to have the pixels a different color.)

I thought there might be a way to do this right in Photoshop...???