I know that Litecoin was designed to be mined with a CPU but then someone figured out how to mine it with a GPU.
Has anyone figure out how to mine Litecoin with an ASIC or FPGA boards, and if not is it conceivably possible? (and by that I mean would it be more effective)
Yes, there are designs for Litecoin mining FPGA bitstreams, but they are not very efficient currently. ASICs are much more efficient and if anyone finds it lucrative to invest in development of Litecoin mining ASICs, they will push out GPU mining. (The efficiency ratio between ASIC and GPU will be lower than with Bitcoin though).
Litecoin uses scrypt instead of sha as its crypto function. Scrypt is a memory hungry algo, so it's very difficult to have efficent implementation on ASIC or FPGA at current technology. This choice was made to prevent ASIC and FPGA specialized mining in favour of more diffuse and generalized mining with standard hardware.
UPDATE After just about 3 months my answer is old. There are company working on ASIC chip for scrypt promising release during current year
would these fpga rigs work on litecoin? i have 2 nr104 total 8 cards with 32gigs of ram... https://nocroom.com/fpga ... like to use these for litecoin.