I have a 2003 Ford Ranger, 3.0 V6 with a 5 speed.  It has almost 80K on it.  I do not take as good of care of the truck as I should.

I have noticed recently that while driving,  my oil pressure gauge drops to 0 for a count of maybe "1 mississippi" then pops right back to a normal indication.  It is not like when I shut the truck off, and the needle drops to zero in a slow arc, but it quick drops, like someone was behind my dash and used their fingers to crank it down as fast as they could, then a second later or so cranks it back to where it normally reads.  I hope that makes sense.

Any ideas?  Oil level is good.  My truck uses barely any oil between oil changes, which like I said I do not keep up on like I should.   I don't use it that often, only when my motorcycle is not an option.  But I am still paying for it, and would like to not blow up the motor any time soon.

It's probably the oil pressure sender flaking out.  They're only like seven or ten bucks, I'd try one of them just for the hell of it.  We had lots of problems with those on 4.6/5.4 powered full size trucks and SUVs.  

Probably sending unit as suggested above BUT where oil pressure is concerned it is far better to be safe then very sorry. Replace it or have it checked, it's a pretty easy thing to do.

I had a similar issue with an 89 ranger.  I'd pull up to a light and the pressure would drop.  I'd press the clutch down (or maybe release the clutch, I don't quite remember...)and the pressure would go back up...sometimes. It was finicky... but it was a fast fluctuation, like when you put your hand over a vacuum hose and the motor whines, and you quickly release it.

Turns out that Ford used a 'fabric' type oil pan seal that would decompose/break apart and fall into the oil pan.  Every now and then some part of the seal would fall off and block the oil pump.  I think when you press the clutch, the pump stops(?) and the blockage falls out.  I thought newer oil pumps had a rubber gasket though to prevent this...

I ended up removing the oil pan and (since it was off) replaced the oil pump and putting a new rubber oil pan seal in.  

Could even be a loose wire.

you can replace the electric one with a mechanical one for little money and not much trouble too.

Ideally, you'd want to verify that you really have oil pressure with a mechanical gauge that screws in place of the pressure sender, but not everyone has mechanical oil pressure gauges to check that.  Given how much pressure senders cost, their well known and problematic nature, and how easy they are to replace (the pressure sender screws into the side of the oil filter housing on a 3.0 if I remember right, and it's kinda easy to whack with the oil filter and/or an oil filter wrench when doing an oil change), I'd definitely try one of those though.

And take better care of your truck.  There's a remote possibility, depending on what you mean by not taking care of it as you should, that there could be sludge built up in the oil pan restricting the oil pump pickup tube.  That's not a good thing.

Thanks for the advice!  I will look into it.  It is due for an oil change soon anyways.