How do I move the Mysql database files from /var/lib/mysql to someother directory

[digvijoy chatterjee]

I have Mysql 4.1.9 on RHES-3.0 installed by rpms..the default socket
path and database creation directory is /var/lib/mysql....now there is a
a dearth of space in /var therefore i would like to move the database
files to something like /usr which has lots of free space , creating
Symlinks does not seem to help.....what is the way out
--Digvijoy