There are numerous tools available on the Internet that perform some kind of ARP based attacks. Below is a list of most well known tools that hackers use to perform ARP attacks like man-in-the-middle attacks.
The Ettercap project was one of the first tools that showed the full power of ARP based attacks. It is GUI based and supports various different kinds of man-in-the-middle and redirection attacks. Through the use of user written plugins lots of attack possibilities like on-the-fly data manipulation are enabled. Very easy to write scripts can compiled with a special compiler and executed by Ettercap. The authors have shown attacks using ettercap on cryptographically secured connections in a Blackhat live demo.
Cain is a highly exhaustive password sniffing tool. Some clicks in the full featured GUI and a man-in-the-middle attack is established. All network traffic is eavesdropped and searched for passwords and hashes. These are automatically attacked using inbuilt password crackers and presented to the user. Cain has inbuilt password sniffing and cracking for FTP, HTTP, IMAP, POP3, ... all in all around 20 protocols. When the victim starts a secure session using e.g. HTTPS, Cain automatically creates a certificate and sends it to the victim. This way secured connections can be eavesdropped.
Besides the above mentioned applications much more tools exist that perform some kind of ARP attack: DSniff, Parasite, Brian, Arppoison, ARPSpoof, Seringe, ARP-sk, ... and so on ...