Selective M of N Transaction

[TalkingAntColony]

Would it be possible to have an m-of-n transaction that would require some keys but not others? For instance, in order to redeem the funds in hypothetical transaction X, we need signatures from the following keys:
 - a master key
 - 2 of N other keys

Transaction X is similar to a 3-of-N multisig transaction, except that one of the keys must be the "master key." I am not very familiar with scripts, but would this functionality be possible? Furthermore, can anyone comment on the possibilities or limitations of scripts?

[Mike Hearn]

Yes that's possible.

<master pubkey> CHECKSIGVERIFY 2 <otherkey1> <otherkey2> CHECKMULTISIGVERIFY