Below are the commands I used. Those in bold are where I did something slightly different in order to change the location where files are stored. In my case I have a powered USB disk mounted on /mnt.
$ sudo -i
[sudo] password for marc:
# apt-get install apache2 php5 php5-gd php-xml-parser \
php5-intl php5-sqlite php5-mysql smbclient curl \
...a bunch of packages installed...
# cd /var/www/
# tar jxf ~marc/owncloud-4.5.5.tar.bz2
# chown -R www-data:www-data owncloud/apps
# chown -R www-data:www-data owncloud/config
# mkdir /mnt/owncloud-data
# chown www-data:www-data /mnt/owncloud-data
# ln -s /mnt/owncloud-data/ /var/www/owncloud/data
Then point a browser to http://raspberrypi.local/owncloud and take all the defaults. That is leave the file location as
Finally go download the sync clients from http://owncloud.org/sync-clients/ and drag-n-drop files in your ~/owncloud.
For testing I had ~180M of files in my ~/owncloud directory and the apache2 process hammered the RPi cpu for a while for the first sync from my desktop.