hello all I just ordered a 13" MBA and am very excited to use it. I've always been a desktop user and this is going to be my first laptop. I was wondering the best way to preserve the battery and battery usage. I'm going to have my MBA at my work station a lot and was wondering should I always keep the MBA plugged in and charging when I'm at work or is it better to let the battery drain and then recharge it when its empty. Or maybe it doesnt matter either way. Also is it like other laptops where the computers performance is better when its plugged into the wall, or does the MBA work the same regardless if its plugged in or not? Thanks!