This crontab entry will email you a report of all the files modified within the past 24 hours.

find $HOME -mtime 0

Search for files in your home directory which have been modified in the last twenty-four hours. This command works this way because the time since each file was last modified is divided by 24 hours and any remainder is discarded. That means that to match -mtime 0, a file will have to have a modification in the past which is less than 24 hours ago.

http://linux.about.com/od/commands/l/blcmdl5_crontab.htm

Describes how to set up a cron job, so the command will execute periodically and email you the results.

MAILTO=me

5 0 * * * find $HOME/public_html -mtime 0

This simple command will let you know when files have been added to your server. You may want to disallow some files or directories.