External HDD?

[PuddingKnife]

So I currently dual boot XP and Ubuntu on my laptop. The singular reason for the dual boot is that I play World of Warcraft.
I have allocated 25 gigs to my XP partition. Well, I recently decided to upgrade to Wrath of the Lich King which is a 15 gig download. I only have 6 gigs of free space currently on my XP partition, SO ..

Is it possible to buy an external hard drive, install WoW on it, and run it from my XP parttion?

Or should I install XP and WoW on an external HDD and play it like that? Would I experience any lag playing like that, since the HDD would most likely connect through a USB?

I have zero experience with external hard drives, so Im not exactly sure what direction I should go in ..

Ideas?

[Polygon]

yeah you can install it to your external hard drive, loading times will be longer because i/o from a external drive is slower then SATA or IDE,unless you get a e-sata drive, then its only a bit slower or maybe even the same.