Call Blizzard.
Nothing else needed...

If you search around on the Blizzard support website you'll find a couple articles about getting cd-keys replaced. IIRC you'll need to send them the cd case. Though the cd-key for starcraft should be printed/stickered on the cd case... (or at least it is for my two copies, bought 8 years apart)

dude it's like twenty bucks and gives you a free 14 day wow trial to buy it new. I mean, I've bought it time and again, and I always sold off the trial for some cash.
just buy the game.

Considering Blizzard is still actively selling and supporting SC (they just patched again this week), I really doubt we will see it on GOG anytime soon, if ever.

It won't help you now, but a trick I learned from my flatmate is to get a CD marker pen and write the key on the disk itself. :)

I even lost my Broodwar CD somehow. Lucky me found a full version of Broodwar on a games magazine lately.
Funny thing, i lost the CD long ago, and i did not buy a games magazin for years, too. So i had a working copy of Broodwar all the years i missed my original CD, without knowing.
Similar with Diablo II, lost it too, somehow. At least 1 or 2 CDs. Found them recently, although i searched everything now and then.

In regards using a crack/keygen being illegal, that really depends on your location. In the US the DMCA does make using such workarounds for a game you bought illegal, but in most other parts of the world (including Canada, for now) it is not illegal. Having said that, it would be nice of Blizzard to provide a way to legitimately get the game working again.

you can digitally d/l starcraft/diablo, etc from blizzard if you have your cd keys still.

Thats good for the people who lost the CD, but it doesn't help you if you need the CD Key.
Actually, i just found out, while registering what i got in the Blizzard Store, that i lost my Diablo II Key, as i found the CDs, but not the casing.
I also miss like everything of Diablo I but the manual.
As i do not want to play this games online, at least not at the moment, it's not that bad. But still...

Funny how forcing you to buy the same game AGAIN is not considered illegal, isn't it? It's almost like the company had every right imaginable, and you - the legal buyer - had none. Somehow that doesn't sound good with the phrase "land of the free", which just so happens to be in the US national anthem...

You mean "land of the free corporate bailouts"?

yeah I already said i had called them. They told me there was no legal way for me to get the game to work again and i would have to buy a new copy. They told me they only replace cd keys whithin 30 days of purchase. My CD key was on the back of the manual.