The large external hard drives are the second best way to go. The best way to go is to lease server space from a reputable Internet hosting company. Leasing plans run as long as $4 a month (maybe lower) and you get unlimited storage. The major benefit, as long as you go with a reputable service provider all of your data will be hosted on severs with RAID controllers as well as offsite Disaster Recover centers. Your data is saved on 3 or 4 maybe more different drives all at the same time, so as long as at least one of those drives is opeartional, all of your data will be secured. And even if the facility where those drives are burns up and they are all destryoed, the company will have another image of your data saved at another facilty.
What do you think companies do with their data??? as any decent sized business owner what they do with their data, I gurantee they don't have dozens of hard drives locked up in a fire safe.
The side benefit of this, especially if you are getting into photography, is that you will also have the ability to have your own domain name and website.
The down side (which is why more people don't recommend this) is that there is a learning curve. It isn't as simple as plugging in a drive and copying data... at a minimum you have to learn how to FTP to a server... which if you use the right program is fairly straigth forward and simple to do. If you want to get into creating a website, its a little more difficult, but with the multitude of website creators out there, there is a pretty short learning curve there also.
Personally, I have an 80GB internal secondary hard drive that I use for temporary storage for my photos... that has about 3 years worth of pictures on it. I also have an external 100GB drive that I back up that entire 80GB drive on. Every few weeks, or when I think about it, I'll ftp everything to my web server. My web server archives about 11 years of photos on it. If there is anything I want to review that is older than the 3 years I have locally, I can simply download it from my webserver.
If at any given point I lose either of my two at home drives, I'm assured that the data is recoverable. And in the event a disaters hits and I lose both drives, I'll still have everything saved online. Depending on how good I am at backing up, I'll probably lose a few days...a month at most. I'm still looking for a relyable real-time automatic offsite backup utility.