multiple db connections

We are trying to port our pure java e-commerce software to postgres. I am using database pooling with jdbc during an init stage of the main servlet that dishes out the html content to the users. (we must use pooling, because it takes too darn long to get a connection, and we need our web pages to respond quickly)

My problem is that we use multiple databases per web request. With other db's, I can make a connection to a central db, and then select .. from <database>.<table> and make sure permissions are such, that I can hop databases with just one connection I get from the pool.

I can't find a similiar technique in postgres. Am I missing a way to hop databases w/o having to create a new connection ?? It is adding 5x the performance hit if I have to get a NEW connection everytime I need to hop. I hate to have to create a connection pool for every database we have on our box. (worried about memory consumption)

Thanks ....