Microsoft Office Document Imaging on OS X?

Microsoft Office Document Imaging is not part of the Mac. You'll have to assemble the different pieces of it using other programs.

For OCR, you can use VueScan, Adobe Acrobat, or other OCR apps.
For assembling scans into multi-page PDF documents, you can use Apple Preview or Adobe Acrobat.

You can also browse, preview, and organize your collection using Microsoft Expression Media, Adobe Bridge, or any other file/image browser that supports TIFF files.

Those are just some ideas. There may be better alternatives to be found at macupdate.com or versiontracker.com if you search for what you want to do with the documents.

Most of my documents are currently in jpeg or pdf. A friend recommended putting them in tiff using Microsoft Office Document Imaging. I have a 2001 version of Office on my Macbook which doesn't include MODI but this discussion seems to indicate that Adobe Acrobat works the same way (which I do have). I'm a genealogist so I have scanned or photographed images of historical documents, wills, deeds, etc. as well as photographs and would like to know the best way to format them without taking up huge amounts of space on my computer. I don't want to just put them on disks or flash drives because I want the images linked to the source list in my genealogy software (Reunion).

Elizabeth, it depends on what you need to do with them. If you simply want to collect scans into single package, Apple Preview (the version in Leopard) or Adobe Acrobat will both do it. Frankly, Acrobat is the easier and more professional solution. You can combine multiple scans into a single PDF file straight from Acrobat's File > Combine Files command, and if you want, run OCR on them so that they become searchable. You will also have compression options for saving space, but it may take a little more time to study and test those options to determine what will be the correct settings for your projects, that is, crunching them down while keeping them legible.