i really hope you didn't make it in the default 72dpi. if you did you are SOL. if you made it at a higher DPI (resolution), take the file to kinko's
i made it at the default resolution which was 72. what can i do now? is there anyway that the pic can get enlarged without loosing quality?
you could even go as high as 700. i would do 700 resolution, and use INCHES, not pixels, and go for the size of the poster you want