In Windows, nothing it turns out. In Linux, nothing if it works. If it still isn't working, put those two lines in that file and restart Tor.It makes the program listen on an additional port for local programs only (nothing external from anyone else, just you and your computer). That way Pidgin can connect to it. If pidgin is set to connect to port 9050, but Tor isn't listening on port 9050, it ain't gonna work too well.Again, in Windows, it already is listneing on 9050. It's only in Linux that it wouldn't be.