can you create a smaller photo file to send to my clients like in a proof-sheets style?

Hello photographers, i have a question about sharing a file ;Some of my clients's photos files of about 300 photos take about 3 GB space. How do you share them with clients? Dropbox needs 2 days to downloadand and not user friendly; YouSendIt allows only 2 GB per file, and zipping the file takes the download about 7 hours. How do make a smaller file, reducing size but still being big enough to view details of the photos? is there a way to make a proof-sheet? or is there a photo librairy that can be shared temporarely with the client? anyone with feedback please? Thank you.