Local weather fried one of my legacy machines, an ancient AMD K6 machine running Windows 2000 (the Amigas and MSXs are fine), and with the CPU totally unusable, I thought "this'd make a kickass necklace if I could drill a hole in it". Using my floor drill press (a Grizzly G7944) and a cobalt alloy bit, I got about halfway through. But when I got to the core, I couldn't even scratch it. Like an idiot, I thought trying from the other side would make a difference, which it didn't, and I ended up breaking the bit.
Why did I fail epically to get through? How are CPU's compressed like that and with what materials? How come there aren't flak jackets made of this stuff? Is it that prohibitively expensive?

You will need a "carbide" drill at a minimal . . . even then it might not get through the ceramic. You can purchase ceramic inserted drills but they are expensive to the point of absurdity.
Give it a try with carbide as they are sorta reasonably priced and available almost anywhere. If that fails, your best bet is to take it to a local machine shop and have them put the hole in using a ceramic inserted cutting tool . . . problem might be finding a shop with a selection of "small" diameter ceramic cutting tools.
Some [url=http://ezinearticles.com/?Drilling-Ceramic-Tiles:-How-To-Drill-Holes-In-Ceramic-Tile&id=444316]reference material[/url] . . . sorry, ceramic tile was the only thing I could find not the same but similar steps to drill it even though it not nearly as hard . . . =)
Ceramic is so hard it is brittle and breaks like glass when dropped or suffering impact. It is also very expensive. I have purchased a box of ten ceramic inserts ( 4 cutting edges per insert) where the cost was almost $1,100 for the ten pieces. . . =(
Edit: Diamond tipped drill is sure to work. . . TMI ??? . . . =)

I think the real question is will it stop a supersonic 9mm, 5.56mm or 7.62mm, not much use making armour out of it if it doesn't

My bad . . . sorry
I would NOT trust my life to ceramic armor alone . . . maybe good for one or two shots . . . no impact absorption really.
video
Edit: not promoting Dragon Skin armor BTW . . . =)

Actually, here we have 100.000.000 new recruits, fresh from the (heh heh) academy and ready for the slaug... er... battle. Put them in a tin can with "wings" and a propellant in the back. Oh yeah, some technics mentioned a laser. No, wait, two. Yeah, you have that. Good luck. If you survive, you get your very own TIE Interceptor. If you scratch THAT one, your family gets your post mortem bill.

I do whatever I get asked to do :) Most days I teach, some days, I do assessments on damage and or threats, others I deal with the politics...DoD, State, UN, Education Ministry, US EPA, and whomever else might need me.......I am a non combatant, however do carry if I am outside most FOB's/COS.
I would rather spend my time rebuilding, and teaching but.... doesnt happen that way all the time...
Dragon Skin has problems still in 100+F heat, the military I think still uses Interceptor, which has a newer version coming out sooner or later, which should fix the issue with smaller rounds.
And a 20 m mech would prolly be too top heavy kinda like an MRAP... so a few well placed IED's daisy chained would knock it down :( I'd have to see it would be fun to see at least

@akwater: if they start attacking you with rocket propelled drilling machines, give AMD a call.

Seems I heard it was overly heavy as well??

Hoorah for mass unit tactics!

Nah, I had a set of reinforced steel plate vest once, that sonovabitch was heavy.
Dragon skin has serious problems below -10 and above +100, which in either conflict you can expect problems.
I'd have to agree the ceramic plates do suck but they have had less problems.
Imagine if a solider was killed in Dragon Skin at this point after the military had already banned it, the backlash would suck. However, because I am a civvie im just one of however many there are in the country and so if I was to die, my death would prolly just be reported like all the other civilians here (pending being beheaded or kidnapped... etc)

Hmm, does it matter who tells you to do stuff? Because my place could do with a good clean...