The sticky bit, bzip2 and automatic start of programs upon login

The sticky bit
I am still wondering what exactly the "stick bit" in the file permissions is doing. My suspicion is that if the sticky bit is set for a directory in the group field (chmod g+s foldername) that the permissions are inherited (that is all newly created files in that folder and below will have the same permissions as their parents. But maybe I am wrong as there is still the weird "umask" command that influences permissions of newly created files. I have to figure out how to automatically set the permissions of a specific directory (which is going to be shared among different users to g+rw.

bzip2 and bunzip2
To uncompress a bzip2 file, execute the following command:bunzip2 filename.txt.bz2 (where filename.txt.bz2 is the name of the file you wish to uncompress). The result of this operation is a file called filename.txt. By default, bunzip2 will delete the filename.txt.bz2 file.

Automatic start of programs upon login
To start up automatically a program upon login, e.g. gaim, I just added the following line to the end of my .bash_profile: "gaim &". I don't know whether it's a good way to implement it like this but it works. I then did the mistake to start the vncserver with this method. What happend was, that upon logging in, the vncserver started up. And of course .bash_profile got executed within the first xdisplay of the vncserver (which happens in case of Red Hat 9 to start up KDE as window manager). So from within this session another instance of vncserver was started. this repeated itself until I had about 80 vncservers running on my machine and the speed slowed down dramatically.