(based on http://search.cpan.org/dist/Net-XMPP2/ and its samples)

Usage

jabber-tool-roster-dump

<jid>

<password>

<host>

<port>

jabber-tool-roster-import

<jid>

<password>

<host>

<port>

Examples

Move your roster to another server

jabber-tool-roster-dump user@domain1.org 123456 | \
        jabber-tool-roster-import user@domain2.org 654321

Move ICQ contacts from one jabber transport to another

jabber-tool-roster-dump sergej@qwe.ru 123456 | \
        grep '@icq.qwe.ru' | \
        sed 's#icq.qwe.ru#icq.vrn.asd.ru#' | \
        jabber-tool-roster-import sergej@vrn.asd.ru 654321

Source

http://code.google.com/p/archlinux-stuff/source/browse/trunk/jabber-tools/