Low Oil Pressure

Video: http://www.youtube.com/watch?v=XGN1-wktJQo

Okay, I picked my car up yesterday. Started after the second turn... not bad at all, huh? Well, the oil pressure shot up to 30 psi, so that was nice, and there was hardly any ticking... it just sounded like a regular engine. So I drove it home (about twenty miles) it's pretty much all highway, I was going 60-65 the whole way and it drove nicely. Well half way home the oil pressure had dropped to 10-15, and when I was pulling into my driveway, the oil pressure was almost a 0, and was in the red, so I parked the car and let it idle and it was ticking like it was last year.

Here's what I have noticed.
-When you put the car in drive, the rpms drop, and so does the oil pressure. The rpms bounce around between 700-1000 rpm and the oil pressure dips and rises with the rpm speed.
-When you let the car sit for a few hours and go to start it, the oil pressure goes up to 30psi and the ticking gets really light but after about ten minutes of idling, the psi drops, and the ticking gets heavier.

I think my guage is reading off, I don't think it's possible to drive a car with 0 psi oil pressure without hearing lots of unpleasant noises.

Do you guys think that this is an oil pump failure or bad bearings? The car runs good, and it doesn't knock. Could it be two seperate cases of a bad lifter and a faulty guage?

I took a video, but I am having trouble uploading it, I'll try again later.

EDIT: the car didn't tick at all before the last oil change...