For MySQL 5.0.3 and higher, you can use
BIT. The manual says:
As of MySQL 5.0.3, the BIT data type is used to store bit-field values. A type of BIT(M) enables storage of M-bit values. M can range from 1 to 64.
Otherwise, according to the MySQL manual you can use
BOOLEAN, which are at the moment aliases of tinyint(1):
Bool, Boolean: These types are synonyms for TINYINT(1). A value of zero is considered false. Non-zero values are considered true.
MySQL also states that:
We intend to implement full boolean type handling, in accordance with standard SQL, in a future MySQL release.