Smorgasboard of problems in OSX lately, and now endless kernel panic

This came out fairly long, but really the most relevant and important part I need help with is the first paragraph.

Tonight my latest gen G4 powerbook running the latest OSX.4 had a kernel panic that will now not end. Zapping PRAM or NVRAM didn't do anything, and booting into single user mode gives the "We are hanging in here" message. In the grand tradition of computer crashes, yes, this did occur when I have a 25% of my grade paper due tomorrow at 8am, no joke. What can I do to fix this? Do I need to boot from disc? Do I need to reinstall OSX? Do I need to buy a new 24" iMac? What is causing this?

This actually comes after a string of things going wrong.

Lately, the past few months I suppose, the fan has been running constantly anytime after the machine is on for more than a few minutes. Just endless fan noise, even when it is sleeping,until it is restarted, wherein the fan starts up again after it's on for a few more minutes. I've ignored it because I didn't mind it, but now I'm worried it's related. What could cause/remedy this?

OSX hasn't been particularly slow lately, but every browser I use is, Mozilla is just a crawl and Safari recently stopped working for me altogether, as a recent post I made here indicated. The only odd OSX thing is that the sound randomly decides to repeat a specific sound over and over again for a little less than a minute. Turning the sound down or off works, but if I turn it off when the sound starts and back on again in a few seconds, the sound will still be repeating. This happens in itunes, in WoW, and in Mozilla and Safari. Any ideas about this?

I suppose as a side question, since this is making me heavily consider getting a new machine, what do I need to look for to optimize extremely heavy internet browsing? This is one of my primary uses of my computer, and by heavy, I mean having open maybe 6 windows with around 16 tabs each at a time. Heavy research use going back and forth between tabs and windows, and this has always been a problem on my computers. Would most any new computer be able to handle this, or would I look specifically for ram, cpu power, or even a certain browser?

Thank you for any and all help, I realize this has been quite a long post. My primary concern is the kernel panic situation, but any help with the other questions here is also greatly appreciated.

 

Well, this is a bump. I really need some help as far as how to get the computer to stop kernel panicking, or at least determine if it's dead.

I tried removing the ram, I have one gig stick from datamem and the 512k standard from apple. I removed one stick and tried turning the computer on, zapping pram or vram, and booting into single user. Then I tried with the other stick. Both times, no effect. Still panicking. So this means it's not the ram?

 

Well, the paper's pat due already, and I have another to help me take care of it for now. The professor is letting me have the weekend to finish it over again(I brought the laptop to class and showed her the kernel panic message under single user, she liked it a lot). So I'm making progress on the assignment alright.

But this situation is really bad, and I really want to know if I have any hope or should just go buy a new comp quickly before more assignments start piling up.