Natural sort order

Morning...

What is the fastest way to achieve natural ordering from queries?

I found a function at: 
http://2kan.tumblr.com/post/361326656/postgres-natural-ordering

But it increases the query time from around 0.4msecs to 74msecs...
Might be not much if occasional queries are made..but I use it for 
building
up a hierarchical tree menu in a web application where every msecs 
counts (o;


cheers
richard