Dropbox also

https://www.dropbox.com/ seen there web, I feel these guys seem to know how things is rightly done

Dropbox replaces:

    * Emailing file attachments to yourself and other people
    * Using USB drives to move files between computers
    * Renaming files to keep a history of previous versions
    * Complicated backup software
    * FTP servers, system-specific sharing methods, Network Attached Storage (NAS)

Not convinced yet? Then take a look at our list of features. Otherwise, go ahead and get started:

from wikipeida

and it supports revision history  by use of deltas or delta encoding technology

go here to get a web access to you folder https://www.dropbox.com/photos/

small tip

I can change the icon of the folder, right click->properties

backup

year=`date +%G`
month=`date +%b`
day=`date +%d`
cd ~/.Dropbox-backup/
mkdir $month"_"$day"_"$year

cd $month"_"$day"_"$year
rsync -r ~/Desktop/Dropbox/ .

revision history

dropbox wedside->recent events actully keeps a nice log for what you've done to your file repo