===Inscript keyboard layout===
Even though it might look a bit difficult to start it is the fastest input method.
You can select Malayalam keyboard layout from "keyboard" menu in GNOME Preferences section (in Debian GNU/ Linux Etch it is Panel->Desktop->Preferences->Keyboard).
Fedora 10, you may need to enable SCIM to handle the Input Method. To enable, go to System-->Preferences --> Personal-->Input Method. You can then enable the required languages from the SCIM setup tool. Once you have selected the languages and input scheme, you may have to re-login to make the changes effective. [http://java.sun.com/products/jfc/tsc/articles/InputMethod/malayalam.jpg Inscript [Malayam Keyboard layout].
===Lalitha phonetic keyboard layout===