opening .smi files in Mac OSX

Hi soxcoverfeet,

first of all: WELCOME TO THE DISCUSSIONS!

The .smi extension is an indicator for a Self- Mounting- Image from OS 9. As a first step try to open it with disk utility. For that just drag the smi-file over the disk utility icon.

If it did not work, try this: click the .smi-file and type Apple-i to get the information window. There you should see a checkbox that allows you to define it as Classic-file. Check it so that the file will be opened in Classic and there it should expand correctly. In case you deleted Classic you will have to reinstall it.

These articles might help:
Mac OS: What is a .smi File
Mac OS X: Using Disk Copy disk image files (Disk Copy is now integrated into Disk Utility)
Mac OS 9.1 and Software Updates: .smi Disk Image Volumes Appear Empty
Common error messages when downloading files

If this answered your question please consider granting some stars: Why reward points?

Right now I'm trying to add subtitles to some movies
that I have downloaded. Unfortunately, all of the
subtitle files are .smi and for some reason the disk
mounting image fails after downloading and the files
are worthless. I can't get them to open in
Quicktime, Real Player, or the DIVX player.

I assume you are talking about SAMI files? (Mac's use .smi for something else as well, as mentioned by Gullliver). You might see if Videolan can help:

http://www.videolan.org/vlc/

or this one:

http://www.ffmpegx.com/

Also you might want to search/ask in the forums where the movie makers hang out:

http://discussions.apple.com/category.jspa?categoryID=141
http://discussions.apple.com/category.jspa?categoryID=123

Thanks for your suggestions...but what is classic? I
don't have that checkbox when I "get info." What is
it and where can I get it?

Your Mac cannot run classic, and I don't think classic is even relevant to your question because the kind of .smi files that it is required for are not the ones you are talking about. Did you read my earlier post? Again I suggest you take your question to the forums where movie makers hang out and where somebody might know something about Subtitle files.