ok so most places worth getting into in my area are surrounded by these type of fences.
http://img120.imageshack.us/img120/6421/picture1id9.png
what would be the fastest and most discreet way of getting past these type of fences for both getting in and out.

A rope, about four feet long with a loop tied at one end and a couple of evenly spaced knots in it, like those ropes they used to make you climb in gym class. Two or three pieces of inch and a half steel pipe with endcaps on one end.

Stick the pipes over the tops of a few of the spikes so that the endcaps give you something non-pointy to stand on. Throw the loop over the non-pointy supporting pole, use it to pull yourself up to where you can get ahold of the sides of one of your pipes to pull yourself up. Then get your other foot up on top of one of your pipe endcaps. Use tension against the rope to steady yourself until you're up, then jump off the other side. Bring the rope with you, or just flip it over to the other side so you can get back over to leave.

without getting speared, dig a hole

Whatever you do, don't slip!

Actually, better plan. Those stakes look pretty flimsy. I'll bet you could just cut a hole in that silly thing with a pair of bolt cutters or something, if you didn't feel like going into Jackie Chan mode.

Those things are pretty tough actually.
People did cut through them when they were still made Aluminium, those days are long gone.

__________________

"You can’t have a lasting civilization without plenty of pleasant vices"
-Huxley

Hmm. They looked pretty flimsy and aluminum/tinlike to me.

I guess we're back to either tunneling underneath it or putting something over the spikes to de-sharpify them, then climbing over.

In retrospect, you could also use a wooden plank of sufficient length and thickness. Just drop it overtop of the spikes and dig it into the ground a bit to hold it there, then walk up and over the whole affair. Depending on the height of the fence you could just push the plank off, turn it sideways, and pull it through the slats to use it on the other side.

If you wanted to get fancy, you could cut a channel or build an L shape into one end to catch the spikes and keep the plank from slipping around as much.

How about just unfastening the nuts and taking them off. The bolt is in plain view...

If that fails, get a truck, tie a rope around one of the spikes, tie said rope to truck, drive away. Come back the next night.

Those look more like rivets to me. The ones attaching each section of pikes to the supporting poles could be bolts, but if the fence designers weren't retarded they'd be carriage bolts with the smooth part facing out and the nut on the inside, where you'd need to be a contortionist to get at it.

What about sawing through the metal where the end of the section meets the big pole. Then since they don't go all the way to the ground you should be able to push it enough to slip through.

Sorry if this isnt clear I'm not sure how to word it.