My favourite Jabber Server (Prosody) has a plugin to automatically inject groups into a persons roaster.
I use this at my university to create groups for every semester (MIB1, CSM3, ...) and fill them with the students using a ruby script that dumps LDAP.
My initial problem was that the injected contacts didn't have a name but just their JID. The mod_groups documentation doesn't mention anything related to names, but the sourcecode of the module has this interesting line:

local entryjid, name = line:match("([^=]*)=?(.*)");

This assigns a value to the two variables according to the matches that the regular expression returns.
So to have the names injected, the groups.txt file has to have the JID and the name seperated by an equals sign. So this is what the format looks like:

This way, you can inject jids AND names :)