Hi. I have a charting /scanning program on home trading PC and would like to have the same on my laptop. It involves having a certain folder containing prices,etc located in PC in order for it to operate. In addtion, I would also like to have my photos located in my laptop backed up in case of drive failure. What would be the most appropriate storage device for such. I would think I would need no more than 100GB. Is the USB flash storage which looks like a key chain better than an external hard drive? The former seem to be a tad cheaper. Thanks.