About 550 khash/s on a 5970 using the Reaper V13 demo:)
550 kH/s gets you around 270 LTC/day.
That same 5970 could be mining at 820 MH/s for nearly .6 BTC/day ... which you can turn around and just buy 450 LTC.
Hmm, 270 LTC or 450 LTC. Hard choice

Yeah. I'm not following the LTC-GPU logic train.
I think a lot of bitcoiners are pathological liars who actually trick themselves to believe that they're profiting.