software to block traffic

i was just wondering if there is any software applications that can block all internet access by all software except for a fw specified ones at any given time

eg:/ i block all internet activity on pc except for msn.

i know somebody is going to be rude so il point out that i dont mean a firewall, i have a firewally but in order to achieve what i said i have to block either all traffic or do everything manually.

any help is much appreciated.

and remember to smile... it makes people wonder what you have been up to =D