A kernel panic USUALLY is a sign of a hardware problem more than a software one.
Try taking the RAM chips completely out and reseat by putting them back in. That is the usual hardware problem. Heating and cooling makes them "loose."
The suggestion to boot from a system disk is a good idea because that will either it is one or the other. If it boots, it is software and you should reload. If it doesn't, if it hardware of some kind.
You said you do not have a startup disk but it looks like you DO have internet access. IF you have leopard (10.6) then you have the apple store. Go to the Apple store and buy Lion or Mountain Lion, $29 and you can download and burn it to a DVD or USB disk by making an emergency boot disk.
I left my MacBook open, plugged in, and playing music through iHome speakers all night. When I woke up the next morning it was displaying a gray screen with some lines of code in the upper left corner starting with the word "panic". It looks like the normal kernel panic screen with the darker box in the middle over the big power symbol and the words "You need to restart your computer. Hold down the Power button until it turns off, then press the Power button again." In English, then French, Spanish, German, and I think Chinese... The thing is that the wording in the box doesn't match what apple says it should say, http://support.apple.com/kb/ts3742 the wording is clearly different - and I am running OS X Lion. I suppose it could be a virus imitating a kernel panic? I haven't had much virus experience so I am pretty much shooting in the dark here.
I've already tried re-booting in both regular and safe mode, removing the battery for a day, letting it drain and trying again, which apparently has worked for some people. <div>
I am volunteering in Costa Rica, and I would really love to be able to fix this myself without having to take it to a specialist in the city. Any input or troubleshooting advice is greatly appreciated.