I recently upgraded my server from php4 to php5, I did the usual basic php5 install using apt-get and have had to add various libraries as and when I need them. Doing this is relatively simple on debian with the apt-get command. Simply enter the following into your terminal session:
sudo apt-get install curl libcurl3 libcurl3-dev php5-curl
If you dont have sudo installed then simply enter it without then enter the following to reboot your apache server for the changes to take effect.
sudo /etc/init.d/apache2 restart
Again if you dont have sudo installed then remove it from the line before you press return and cURL will be fully working – enjoy.
