/tmp is too small

[Hendrik Boom <hendrik@topoi.pooq.com>]

I need more space for /tmp.  I though, easy, I'll just take out the /tmp 
entry in /etc/fstab so that it doesn't mount anything on /tmp and uses 
the the space on the root partition, which has more than room enough.  
But then I discover that in my newly installed wheezy system, there *is* 
no /etc/fstab entry for /tmp.  Apparently the kernel, all  by itself, 
decides to mount the tmpfs on /tmp.

How can I get it not to do this?

Or alternatively, how can I enlarge the tmpfs?  I need it enlarged from 
anout 200M to about 2G for this week's project.  Yes, that's a lot bigger 
than my RAM.

-- hendrik