So it's costing the spammer 1 LTC to send these huge transactions (~50kb). Doing the math (ignoring 1024 versus 1000)... 20 LTC for 1mb or 20,000 LTC for 1gb. 20k LTC is only $264 at today's exchange rate. So for someone who hates Litecoin, it only takes a measly $264 to bloat the chain by 1 gig. Not even Bitcoin has a chain that large.

He's actually taking advantage of the relay transaction fees of 0.2 ltc to propagate his transactions and then taking of advantage of the miners who haven't upgraded to write his transactions into blocks.
We could increase the relay transaction fee to the same .1 ltc (it's 0.02 ltc now), but that just means it's 5 times more expensive for him. Or we could increase both fees to 1 ltc and make it 50 times more expensive. Or we could do nothing.

I've create a pool on the liteco.in forum. If you care about Litecoin, please vote: http://liteco.in/threads/what-should-we-do-about-transaction-spam.44/