Postgresql sync databases

I am having a postgres database on my portable and on a server. I would like to keep those two in sync as easy as possible. I know about slony but I am not able to figure out: Does it work when the two servers are not always connected? - I may do changes on the db on my portable when it is not able to reach the other server. Does it work both ways? Can I update the slave and get the updateds pushed to the master? Does it sync changes in the db-structure? The database in question is a geographical database, and occasionally I import a new map as a new table, I am also often adding new view for data processing. If slony is not useable in my case, are there any other usable tools? I've looked at dblink, but that does neither seem to be what I need.