Prebuilding circuits?

[Kees Vonk]

F. Fox wrote:
> Kees Vonk wrote:
>> F. Fox wrote:

>>> I'm assuming that the site you mention is a "normal," unencrypted Web
>>> site - i.e., port 80; let's call that site, Site X.
>>>
>> It is an encrypted site on a none standard port, would that make a
>> difference?
>>
> 
> The non-standard port does, since it may not be part of the default exit
> policy. That would greatly reduce the number of potential exits - and
> your Tor client would likely have to start a circuit just for that site.

So if I understand this correctly you could say that Tor builds circuits 
for ports, not for sites? If that is correct, can I tell Tor to prebuild 
a circuit for a certain port?