What Cindy suggested is a good idea, but the trick with Acacia is to break up the lumps, so stir with a fork or whisk not a spoon and just give it time! It'll dissolve on it's own after about 10 minutes anyway.
But how I usually have it in the morning is either sprinkled over cereal before I pour the soy milk in (it just makes the milk a bit creamier! ) or mixed with my oatmeal before I cook it. Either way it's not an issue. At night I usually just put it in a mug of soy milk and mix it up.
But if you want to add it to something like pasta sauce, mixing it with a little bit of cold water first is a very good idea. Just think how you'd treat cornmeal -it has the same kind of consistency I find.