Lost key (transponder and remote lock/unlock)

[shyeoh]

hi!

I just bought a new yaris 2010 model and shit happens - lost the one set of key (one with 2 button remote and an immobiliser built in)

can someone tell me if i can disable the lost key transponder without going to the dealer or replacing the immobiliser? i guess the remote lock/unlock is not too critical but just don't like the idea that my key is somewhere OUT THERE and it is coded to my car still. i read that i can program a new set of key myself by following the manual but not sure if i can delete out the code without the tester used by toyota.

thanks everybody!