OwnCloud Server

ownCloud is a software suite that provides a location-independent storage area for data

Have php and webserver installed. (I’m using ubuntu 11.10)
$ sudo apt-get install apache2 php5 mysql-server php5-mysql phpmyadmin

Install ownCloud
$ sudo wget http://mirrors.owncloud.org/releases/owncloud-4.5.7.tar.bz2
$ sudo bunzip2 owncloud-4.5.7.tar.bz2
$ sudo tar -xvf owncloud-4.5.7.tar
$ sudo mv owncloud/ /var/www/
$ sudo chown -R www-data:www-data /var/www/owncloud/

Done. Now go to localhost/owncloud
Make ownCloud accessible outside your home network.

You may receive this error:
Your data directory and your files are probably accessible from the internet. The .htaccess file that ownCloud provides is not working. We strongly suggest that you configure your webserver in a way that the data directory is no longer accessible or you move the data directory outside the webserver document root.

This mean that your .htaccess doesn’t have permission to override the php.ini
You don’t have to change anything to make owncloud work but if you want this feature read “Allow htaccess to override php.ini”

To increase amount of data that can be uploaded.
There’s two options you can edit upload_max_filesize and post_max_size in the /etc/php5/apache2/php.ini file or edit the .htaccess if you did the above configuration.