http://dev.mysql.com/doc/refman/5.1/en/create-table.htmlYou can use the TEMPORARY keyword when creating a table. A TEMPORARY table is visible only to the current connection, and is dropped automatically when the connection is closed. This means that two different connections can use the same temporary table name without conflicting with each other or with an existing non-TEMPORARY table of the same name. (The existing table is hidden until the temporary table is dropped.) To create temporary tables, you must have the CREATE TEMPORARY TABLES privilege.

про удаление:
http://dev.mysql.com/doc/refman/5.1/en/drop-table.html The TEMPORARY keyword has the following effects:

* The statement drops only TEMPORARY tables.
* The statement does not end an ongoing transaction.
* No access rights are checked. (A TEMPORARY table is visible only to the session that created it, so no check is necessary.)

Using TEMPORARY is a good way to ensure that you do not accidentally drop a non-TEMPORARY table.