It is very easy about installing CURL to your PHP5 in Ubuntu 10.10 just straight do this in your Terminal.
sudo apt-get install curl libcurl3 libcurl3-dev php5-curl php5-mcrypt
Restart your Apache Server
/etc/init.d/apache2 restart
OR
sudo /etc/init.d/apache2 restart
Welldone! And special thanks to Ivan Kristianto