At the moment I have my source code and resources for my game project on my hard drive, and also backed up on two separate memory sticks, but I was wondering how others go about ensuring the safety of their projects? I know that professionals/companies will have very sophisticated schemes, but of course there are a lot of casual programmers who would not have access to large off-site storage. How do you do it?

Github.

For my "using it now" stuff, I use Dropbox, and that includes any current projects and work. It also includes other things that I feel I might want to access on the go. On top of this, I have my laptop synced as well, so even if Dropbox goes down, I have atleast one other copy there as well. I figure a good rule to go by is to have two backups as constantly made as possible on reliable sources, where reliable doesn't have to be perfect, rather simple and easy, and preferably automatic.

For the more important things, which would be mostly photos, I keep those on CDs/DVDs, and I keep those discs in envelopes and in a safe place. I have understood that optical media, as long as it not kept in the sun, can be very reliable for storage, and so far it has never given me problems, though I use the discs at times to send photos to people and to print them too.

Well I don't have that many "irreplaceable" data, as I am not very materialistic. Most of my stuff is content available on the internet in some way (movies, music, ..) and then my personal stuff which is rather small (code, a few pictures, other miscellaneous stuff). I have my code on Github and on various other websites and I know exactly where to find it, as for the rest it's on a separate hard drive, as well as a USB flash drive which I keep in a secure location and on a remote archival service (encrypted) and is updated once a month or on demand.

But it's important to differentiate backup and archival. A backup needs to be always available (and needs to actually exist and not have been destroyed along with the original version, a.k.a. always store your stuff in two distinct physical locations, and a backup is not a backup if it isn't backed up) and it should be fast and painless to restore a backup. On the other hand, data archival need not be fast, and doesn't have to be instantly accessible, but data should be safely kept at rest on durable media such as optical media, in more than one location. It should also be possible to search an archive to look for what you want, whereas that's not really necessary for a backup since if you need the backup you probably need all of it (a backup is not a version control system, and vice versa). They are different things.

And frob's point is very important - always verify your restoration procedure works. Otherwise the only time you'll find out it doesn't work is when you are actually trying to get your stuff back during an emergency, and then you're screwed.

I was using github, but now it became clumsy, and it can't hold .obj files for some reason. So I switched to Ubuntu One cloud. Or you can use DropBox, but Ubuntu cloud gives you 5Gb for free, so I choose it.