What Mac application should I use to allow me to connect to Cisco VPN?
Try the Cisco VPN Client for Mac.
If you using snow leopard you have a cisco compatible VPN client built in. Go System Preferences -> Network -> Click the + sign to create a new interface. Choose VPN -> Cisco IPSec and the name it. Enter the details and then click Show VPN status in menu bar. This will make it easier to re-connect with the menu bar in the future.
Also if its a new cisco ASA if might already come with a SSL VPN which is java based and works great on any OS. You can reach it via https://your-vpn-hostname if your administrator has configured it.
You could also try Equinux VPN Tracker, if you have the need to connect to other vendors of VPN concentrators.