Multilingual application, ORDER BY w/ different locales?

Hi!

We are using postgres as RDBMS in an web application that is translated to 
about a dozen different languages. Some users get puzzled about the sorting 
order in lists, since we have to choose only one locale for all ORDER BY 
queries. I am dreaming of a SET LC_COLLATE or simliar command that will 
only affect my session, not all other users.

I know this is not implemented in postgres. How impossible is it to add 
this feature, and what implications would pg suffer? All discussions 
regarding locale problems in postgres are about LIKE indexing. For us, 
collating is more important. Can we help?

/Palle