(1) Use the Distiller from Acrobat 4.05 or better.
(2) Select 'Embed all fonts' (on the Distiller Settings | Job Options | fonts menu)
Otherwise Acrobat may include font references in the PDF file to fonts on your computer that may not be available on other computers.
You can check your output for portability if you uncheck the 'Use local fonts' option of the 'View' menu of Acrobat while examining the resulting file for missing elements (especially symbols, Greek letters, brackets, etc but sometimes elements as common as commas).
A detailed document describing how to create portable PDF files is on the National Science Foundation web site at www.fastlane.nsf.gov/a1/pdfcreat.htm to aid applicants in the submission of NSF grant applications. They also supply a 'Job Options' file at www.fastlane.nsf.gov/attachA.htm that configures your Acrobat software to generate files that will display and print correctly on any client computer. The default configuration for Acrobat does not do this. We are happy to accept documents formatted according to the NSF guidelines, so feel free to use the Fastlane job options file for us.