Not sure where you live, but here in the UK several phone companies seem to give out free SIM cards. See if you can get one from the network that the phone is locked to.
If you don't know which network it is locked to, see if your mates will put their SIM cards from different networks into the phone until one works. You could then use that SIM card to do the quick access patch and SIM lock patch to unlock it.
Just my thoughts.
Darren