Can I specify more Recipient Addresses for this Mailbox?

I'd like to be able to alias mailboxes to point to another mailbox and have that mailbox handle various tasks associated with it. This is partly prompted by this thread: http://getsatisfaction.com/otherinbox...

So, in that scenario, say I have a mailbox called Travel and I want to have email addresses like orbitz@myoib, travelocity@myoib, etc that pipe into Travel. I didn't see a way to do that. If I send a new email to an address not associated with that mailbox, create a new one. So, if I book a flight with Southwest and send it to LUV@myoib, it won't show in Travel because it's not yet associated. When I see the email, it should be a few clicks to set it to dump those emails into travel from then on.

Here's the advantage, and how I would envision using this. I've set up a forward and filter as discussed in the other thread with Gmail. Rather than creating a filter for each potential email address I might have travel plans sent to, I would just create one for Travel and then any message that gets dumped into Travel would be forwarded to this address. Note that the mailbox that it is in and not the address it was sent to should be reflected in the forwarded email for streamlining the process. But, I still get the advantage of having separate addresses for all those services so I can see who's contributing to spam.

I hope what I'm asking for makes sense. To my mind, all OIB is is a bunch of email aliases, so this is a natural progression in my view.