Best implementation of PATRICIA

Hello!

I'm working on a project requiring fast query like 'does ADDRESS belongs 
to SET OF NETWORKS?'. Naturally, such a query is better implemented 
using PATRICIA, but building PATRICIA tree is a relatively long task and 
is better to be done once, for instance, at server startup.

I'm thinking of implementing such a tree using stored procedures, and 
looking for advise from postgresql-hackers: how can I hook startup of 
server?

Idea of having something like a blob to store and restore PATRICIA tree 
may be better suited to standard SQL, but I'm looking for more elegant 
solution. Or am I totally wrong?

Alex.