Prebuilding circuits?

[Kees Vonk]

I have found that while using Tor the first connection to a site always 
times out. As I understand it, this is because Tor is still building a 
circuit to the site in question. Now there are certain sites I access a 
lot, and it would be good if I could tell Tor to build a circuit to the 
site at start up time, that way I would always have an available circuit.

Can someone please tell me if and how this is possible. If I have 
totally misunderstood what is going on, please let me know as well.

Thanks