On one server, when I run:
mysql> select now();
+---------------------+
| now() |
+---------------------+
| 2009-05-30 16:54:29 |
+---------
You can specify the server's default timezone when you start it, see http://dev.mysql.com/doc/refman/5.1/en/server-options.html and specifically the --default-time-zone=timezone
option. You can check the global and session time zones with
SELECT @@global.time_zone, @@session.time_zone;
set either or both with the SET
statement, &c; see http://dev.mysql.com/doc/refman/5.1/en/time-zone-support.html for many more details.