sick cat -- need some advice

Last night when we were coming home, DH saw a cat under my dad's car in the driveway.
The cat was not in good shape. I went into get it some food and when I came back out it was gone. I found it wandering on the side of the house. I tried to give it a can of tuna, but it sniffed it and started to walk away. It was skin and bones and was walking around very slowly, and seemed like it was disoriented.
I picked it up, and it just laid kind of limp in my arms, didn't even try to get away. I looked at its face and there was gunk coming out of one of its eyes, and I am not even sure if it had two eyes, or the other one was just so crusty.
I brought it to the door in the back of the house to ask DH and my parents what they thought i should do, and tried putting it back down to see if it would eat... and it walked away. I thought it would stop but it kept going.. it was dark out - and I don't know where it went. I tried looking for it with a flashlight, but I think it went under the fence into the neighbor's yard. I was so upset for this poor cat...

If I see this cat again tonight, what should I do? I was thinking of bringing it to the emergency vet, but i can't afford to pay for the extensive care I am sure it needs... I thought about bringing it to little shelter or the town humane society last night, but they both were closed at that time...
I really hope it didn't die last night, I was so sad seeing it in such misery.

Re: sick cat -- need some advice

If you find it again, take it to a vet and tell them it's a stray. Most vets will assume the responsibility of the care and not expect you to.