In theory yes it might be possible, but the N770 doesn't have any support for packages like that. So for installation i find it much better to stay with .deb that is used now.

.tar.gz and .tar.bz2 mostly contains source code when used to distribute programs.

The reason for requesting .gz and .bz2 is because when sending patches (textfiles containing changes to source code) they sometimes get pretty large and then it would be great to be able to use gz or bz2 as they are the standard used on Linux.

cheers!