Help on maintaining pgsql/data folder size

Hi all,

I am using PostgreSQL 7.4.3. The problem I am facing is that the size of
pgsql/data folder keeps increasing and at a point the it takes up all the
disk space and it freezes the system. The pg_xlog and the pg_clog folders
are taking up most of the disk space. In the documentation, it says that I
have to move the pg_xlog folder to some other location and create a symbolic
link to that path from the original path. But the problem is for our
application, we are using a 512 MB compact flash and there is no
harddisk....so I need to check the database folder size somehow. Could
anyone help me out in this regard.
Between in order to recover the disk space, I am using a script which
vacuums the database regularly.

Thanks in advance for all your valuable inputs.

Regards,
Pradeep