I have about a pound of whey protein left and I want to use it up as a meal replacement about once or twice a day, like after workout and another maybe when i'm pressed for time...is this a good idea and can i stay within the zone?

Thanks mates!

Absolutely! Whey protein is very favorable on Zone. Just remember to balance it with fat and carbs.
Are you converting to Zone from your current plan?

yeap,

i'm converting, this seems more like my speed...thanks for the response..also..I see that I need 144g of protein... so that's 20 blocks of protein a day? and 20 blocks of carbs and 20 blocks of fat a day and 4 blocks per meal at 5 meals a day. Correct?

thanks mate!

Yes, the Zone is quite flexible and is something you can do for life. There are so many benefits besides weight loss.
You seem to have a handle on it.
Each block = 9gC, 7gP, 3gF
Therefore, in your example of a 4 block meal, you would eat
36gC, 28gP, 12gF
Fat can be confusing. I've posted on it before in this forum.
You can split your blocks up any way you want. By that I mean, you don't have to have 4 block meals ~ you can have 2 block meals more often if you want. In fact, it's recommended. 5 meals per day is just the minimum. {I guess there's a lot of people out there who have a hard time eating often} {I'm not one of them}
Remember:
Lots of water (1/2 your body weight in ounces - minimum)
Eat (at least one block within one hour of waking)
Eat one block before going to bed (within 1/2 hour or so)
(This is important to stabilize your insulin ~ the Zone is all about controlling insulin)

Thanks for responding...

I too don't have a problem any 5+ small meals a day..I enjoy it. I usually do morning cardio on an empty stomach and then a weight workout around 10 or so before i have that second meal and then thereafter stay active i.e, tennis or etc. So i may have to up my protein, but i'll try the 4 blocks for about a week or to and see how it goes.

It is recommended to be "in Zone" and therefore, eating at least one block before exercising. (Also, post workout snack or meal)
It is not recomended to increase protein alone. Remember, your protein requirement is based on your lbm and activity factor. That determines your total blocks. So, if you need to increase ~ you increase blocks not protein alone.
I hope this makes sense.