I recently got my hands on a brand new external memory, the Iomega 250 GB, if your looking at buying external memory and need something quite hefty, have a little read of my review!
As a University Architecture student I am often using Auto CAD which is quite memory intensive, for my birthday I asked my mum if she could pick me up a cheapish memory for about 40 pounds, something to back my work up in case my laptop ever dies! So she go's and gets me 250 GB!
There isn't a great deal I can say about hard drives, you plug them in and drag drop what files you want to save, however, this hard drive does have a few points that are worth noting if your looking to purchase...
1. It took me an hour to format the hard drive before I could use it, some hard drives are pre formatted and you can just plug and go, this one had me reading through the manual, not really what I wanted and obviously if your looking for a hard drive for immediate use, not what you would want either. So do bare in mind it does take a while to format the Iomega memory.
2. It was quite expensive, retailing at around £100 , I know it's a lot of memory, but for much cheaper you can get a reasonable amount, you may not even need as much as 250 GB, so when it comes to external memory, id shop around and know roughly how much you need.
Other than those two points, once the hard drive is formatted your away! I've been using it for a few days now, transferred big video clips and music etc with no problems, I've even dropped it once and its working fine, I would recommend this hard drive if you need a large amount of space and have the time to format it at roughly one hour!
Hope this helps!