wget http://www.magentocommerce.com/downloads/assets/1.0/magento-1.0.tar.gz
wget http://www.magentocommerce.com/downloads/assets/1.0/magento-sample-data-1.0.tar.gz
tar -zxvf magento-1.0.tar.gz
tar -zxvf magento-sample-data-1.0.tar.gz
mv magento-sample-data-1.0/media/* magento/media/
mv magento-sample-data-1.0/magento_sample_data_for_1.0.sql magento/data.sql
cd magento
chmod o+w var var/.htaccess app/etc
chmod -R o+w media
mysql -u DBUSER -pDBPASS DBNAME < data.sql
./pear mage-setup .
./pear install -f magento-core/Mage_All_Latest
rm -rf downloader/pearlib/cache/* downloader/pearlib/download/*
cd ..
chmod -R 777 magento
Setup a database and assign a user to it. Replace DBUSER, DBPASS, and DBNAME above. Copy and paste the entire thing. After it finishes just go through the web-based installer.