You can get an external one to throw all your videos and crap on while you keep the original one open for games. However, to get an external hard drive to work, you have to format it (or a partition) to FAT32 using a program like Partition Magic otherwise, the PS3 wont recognize the hard drive.
That's what I was able to do, I took my external hard drive and formatted 80gigs of it to FAT32 and the PS3 was able to read it.







