I was wondering what would be the best file format to save an .ai file in so it could be used in other programs, such as Microsoft word, while retaining the same vector quality as the original .ai file.

Thanks for your reply.
:)

EPS but it will only work in Word if you installed the EPS file format when you installed Word/Office (custom install). Other than that only WMF will work I think.

EPS is the most universal though. If you are using a newer version of illustrator, save down to an older version like 8. It will make the file more compatible.

:)