Multi master use case?

Hello,

A client of ours has always had problems with slow internet connectivity - they are in a part of the country where that
isa problem. There are a few hundred staff sharing a couple of asymmetric (ADSL) connections. One issue is with
accessingtheir web-based Postgres app, which we host. Now they don't want to run it internally for a lot of the usual
reasons,not least they have many distributed workers and trying to serve data from an already congested spot would be a
nonstarter. 

Is this a case for multi master do you think? I.e. running one on the internet, one locally.

Looking through the wiki

http://wiki.postgresql.org/wiki/Replication,_Clustering,_and_Connection_Pooling

it seems there are a few solutions that have now gained maturity. Something like rubyrep sounds ideal. It would have to
dealwith 
a) a flaky local connection
b) changing schemas (new tables, fields, views etc.) as well as data

Create/update/delete frequencies are reasonably low, generally individuals updating single records so of the order of
thousandsper day max. 

Any experiences/thoughts?

Oliver Kohll
www.gtwm.co.uk