First I'll ask the question and you can read background if you like:

What can I do to reduce file size?

It's not that I care about using an entire CD for a single image I just want to be able to plot to jpeg for the printer and PDF so I can show it to people who aren't as familiar with graphics programs as I am. Photoshop just kicks files of the 100's of mb size back to me and says I don't have the memory to save to jpeg or pdf.

I'm moderately knowledgeable about photoshop so don't spare any large words (plus I'll ask if I don't understand something). I have to do a presentation board for a project which will, in it's finished state, be 30"X42". In the past my printer has always required images to be 300dpi so I've gotten used to working at that level, however, it creates a ridiculously large PSD (a hair over 1GB).

After merging and flattening I brought the file size down to around 650mb which is still too large a file for me to save as a jpeg or pdf so I'm left with tiff. Saving a tiff doesn't change the file size it just makes it a more widely compatible image format and I'll be calling tomorrow to make sure they can print from a tif (or maybe a PSD so I can skip this whole pain in the butt step in the future) but I was wondering if there are any other options available to me to reduce file size.