Need some suggestions and info about an External Hdd for my ThinkPad R61. What do you think?

Hey, all. I just bought a nice little Lenovo, with one problem: I only have something like 92mb of disk storage to split between two OSes, and I really, really would like more, because I'd like to do video editing in the near future.

What you need to know:
It has: USB 2.0, ExpressCard (both 26 and 68 pin), FireWire(1394), Intel 802.11(g), BlueTooth, and a removable DVD drive (can I put an HDD there?)

Performance is crucial, since I'd like for it to have a similar data transfer rate as my 7200rpm. I'd like to be able to watch movies, edit movies, load games, etc, from this external drive.

Size is also important, since I'd plan on taking it with me in my laptop case.

I'd rather not replace the internal Hdd instead (seeing as how it took me two days to get everything reformatted and setup on both partitions, I don't want to go through all that again)

What I need to know:
Which interface can I get a good Hdd for? And which one would give me the best performance? Also, how would it compare to my 7200rpm drive as far as speed?

I appreciate your input. Thanks.

 

Actually, after all that, don't worry about responding. I just found out I can swap out my disc driver slot for an HDD. That'll do! Have a good one, all.