I would have no problem lending you, but "I'll repay to your sending address only." wont work because I would send from mtgox...
In case you might be able to send to another address and would accept 0.3BTC for 0.4BTC in return in max 7 days, let me know.
@ganabb, he is asking for $30 with a 2 years old account while organizing
large group buys, so I think collateral aint really necessary, dont you agree?