This is simple project which should provide templating abilities for Arduino 
with Ethernet Shield (with SD card socket).

Summary:
You can parse files on SD card and Arduino will replace strings #{x} with
output of function. You define in sketch which mnemonics (downcase letters)
are associated with which function.

You can make more compliacted HTML pages and not being limited by RAM/flash
size. 

You can read more about what and how:

http://starter-kit.nettigo.eu/2011/p4a-php-for-arduino-part-1/
http://starter-kit.nettigo.eu/2011/p4a-php-for-arduino-part-2/