Programming a new key with only the Valet Key

It has to be possible... How do I get a new Primary key to program other keys with when all I have is a Valet key.

The Valet key appears to do everything that I need it to do, but I only have the one key! I can't program new transponder keys off of this one. The factory says they can do it but I'm told it costs up to $3,000 to do it. Can I order a replacement part? Can I hook my computer up through some special cable and do it?

All I want is a Primary Key again when all I have is the Valet key. If I lose this key, I have the world's largest paper weight. (well, I'm sure there are larger but you get the point.)

Oah yeah...
2003 Toyota Highlander 4wd
Let me know if you need any other info.