You can make some improvements by moving /tmp and /var/tmp to your RAM.
First, edit /etc/fstab and add following lines:
tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0
tmpfs /var/tmp tmpfs defaults,noatime,mode=1777 0 0
Next, remove all files from /tmp and /var/tmp and mount new RAM partitions:
sudo /etc/init.d/sysklogd stop
sudo rm -rf /tmp/*
sudo rm -rf /var/tmp/*
sudo mount -a
sudo /etc/init.d/sysklogd start
Also, you can move Firefox cache to RAM. Type about:config in Firefox address bar and hit Enter. Right click in the parameter listing and select New->String. Set the preference name to browser.cache.disk.parent_directory and set the value to /tmp.
Restart Firefox.