Expired Yeast (Coopers)

I'm a complete newbie. I bought some of my own equipment yesterday and am borrowing a carboy and a boil pot on Monday. I'm doing a 5 gallon brew with 6 pounds of light malt extract, cascade hops, and about 2 pounds of cracked grain (I'm not sure any of this has bearing on the yeast I'm using, but I'm so excited I'll tell you anyway).

But anyway, when I got home I was looking everything over (and drooling) and noticed the yeast, which is a packet of Coopers yeast, is expired in June of 2010!!

I'm going back Tuesday to get new yeast (they aren't open Monday, sadly enough). Should I keep the yeast and use it? If I rehydrate it and it foams, is it still viable? I really don't want to ruin the very first batch of beer I do.

Advice? (Besides checking the expiration date before I buy something!).

Bonnie

You could try to use it, it definitely would not hurt your beer if the yeast is dead. When rehydrating it, chances are you won't see any foam. Brewers yeast isn't fast, unlike bread yeast which will start foaming in a matter of minutes.
Wait 24 hours after pitching, and recheck for any signs of fermentation. If its fermenting, great! If not, well then buy another fresh packet of yeast. It won't hurt your beer to sit for a day or so, just keep it covered as much as possible.

Also, welcome to the addiction!

Forget the Coopers and buy some Fermentis S-05.
Foaming on rehydration is not a real sign of viability. Also expired yeast does not mean it still won't work, but with Coopers it isn't very good to begin with. Especially if it is the small 7 gram packet.