Hi guys, I'm a PC user and am finally biting the bullet and buying an MBP. I'd like to buy the 2.4ghz MBP and am debating whether to get it with the 250gb HDD (in which case I could just walk into a store and pick one up...instant gratification! LOL) or upgrade it to the 320gb HDD (in which case I'd have to order it online). While I don't think I need more than 250gb of hard drive space it's always nice to have extra. If I pick one up in store could I just have the HDD upgraded, or would it be best cost-wise and time-wise to just customize it and order it online through the website? Thanks in advance.