All of these transactions use scripts. These scripts can be encoded as a script hash and used in a Pay-to-script-hash (P2SH) output which corresponds to a Bitcoin address beginning with a '3'.
Multisignature addresses have scripts of the format
OP_0 <pubkey 1> ... <pubkey n> OP_n OP_CHECKMULTISIG
where n is less than 15. The OP_n indicates how many of the previous public keys are required in order to spend from that address.
Escrow transactions are basically smart contracts. Bitcoin doesn't really support this well yet. These smart contracts are really just complex scripts.
Timed transactions are transactions that use the nLocktime field of the transaction. This field prevents the transaction from being confirmed until a certain time. They can also be used in scripts for P2SH addresses which use OP_CHECKLOCKTIMEVERIFY which will ensure that Bitcoin cannot be spent from that address until the nLocktime has passed.