You'll need a portable folder of Pidgin 2.10+. By example: E:\PidginPortable.
Copy all this files to that folder: E:\PidginPortable\App\Pidgin
Manage your accounts, you'll see the new Communicator Protocol :)
Pidgin Portable with Office Communicator in Windows
If you are using Ubuntu, just install the pidgin-sipe package from the Ubuntu Software Center :)