I applied for Half Rate Carer's allowance... (I recieve Disability Allowance, and am caring for my mother)...
I applied on Sept 27th 2007 (The day it became available!)... I recieved a letter informing me of being awarded it on Dec 20th 2007... To be fair, I recieved a cheque for the backdated payment (€1,284) on the 24th Dec...
So my advice is to plan for a wait of three months, and if it's any shorter, well that's a bonus!...