So, Chicago says that your powerpoint must be less than 10MB to upload into the system. Mine is right over 5MB and refused to upload. The alternative is to convert the file into a .pdf file which will be considerably smaller. Warning: I had a little difficulty since I had some cutesy labels that were tilted - most of these solutions mangled my cutesy label!
Some solutions for those even more last minute than me (or I suppose R2)
1. createpdf.adobe.com - sign up for an account and you get 5 free chances to convert your file to a pdf.
2. www.pdfonline.com/easypdf - This one was pretty good, and kept the tilted labels in the right place. However, with the free trial, there was a small logo on the bottom right hand side and my photos were a little fuzzy. I also though the one time usage fee of $15 was high.
3. www.go2pdf.com/download.html - POS. Don't bother.
My solution after trying all of these? I uploaded my file to www.transferbigfiles.com. My friend who has macromedia 8 downloaded it, converted to pdf and sent it back to me. My tilted labels stayed tilted. One of the pictures ended up looking fuzzier than I wanted it to, but I noticed all solutions resulted in degradation of quality.