I do not know anyone that uses the express drives on their laptop unless they tinker too much and blow their internal wireless cards. Those drives just hang out and do nothing. Since the average laptop hangs out with only about 60-120 GB of hard drive space, a few extra GB never hurt anyone. A-Data made some express slot friendly drives which add either 16 or 32 GB without the bulk of carrying around another drive separately. Caters to your laziness and your lack of space. 16/32 GB for 65.99/129.99 .

They are actually currently sold out but sold here and here. If you want them both and want to combine shipping they are both available at the second link, just the smaller one is $4 more.