XEP-0080 allows to broadcast current location and the buddy can display it on a map using e.g. empathy.
This worked some time back very well but is broken now: no contacts are displayed on View->Contacts on Map
-> n900/telepathy-gabble/azimuth - contact email@example.com
My logs: http://bokomoko.de/~rd/telepathy/
There was also some discussion on the mailing list on this issue:
I use telepathy-gabble (0.16.1) and emapthy (126.96.36.199) from Debian wheezy (testing).
If it helps to localize the bug, I can build from source to get more debug information.