We are two geeks doing a lot of coding, documentation and designing (PhotoShop, Illustrator, InDesign and FireWorks).

We both carry a laptop, have our personal stationary PC's and then we have a couple o' iMac's that we dedicate to working with these stuff together.

It is important that we can access our files from everywhere.
I've considered a simple FTP accessible NAS on the network of the iMac's (70% of the creativity happens here). But FTP sometimes becomes annoying to use (have to open up FTP application, etc.).

Also I've considered to use Dropbox, but I'm not the biggest fan of cloud storage - it is important to us that these things remains ours and that they are always accessible.
Another issue here is the huuge graphics files that will eat bandwidth everytime we open up another PC.

Well - any - to you obvious - suggestion of software or technology for this scenario?

Have a nice evening.

This is an interesting requirement and it is probably becoming much more common. I had a look at what is available and I came across Gluster. The combination of that with Amazon Web services may give you high-capacity, private cloud storage with some sync'ing capability. I only skimmed the surface so you will need to dig a lot deeper but it appears that it may provide quite a bit of what you need. I'm not sure if the sync'ing capability is as automatic as Mozy or Dropbox so that would need to be checked out. It's ability to share and sync data across multiple end-points also needs some checking.

You may not like cloud storage but other than having your own server and using something like Gluster on it (which is also an option but at higher cost) there aren't any other obvious solutions to give you shared access from multiple end points. It makes you dependent on the internet and cloud service being available but if you can sync on a regular basis, then all of the machines could still operate offline during an outage.

This page provides some user comments on Gluster.

I've seen a need for something like this for awhile, and I bet there are plenty of programmers on here that would be willing to take a crack at making a custom app to do this. Actually, I'd be willing to do it, even make it open source.

Dropbox does have a LAN option, that if your syncing computers with their server, and they are both on the same LAN, the transfer between computers is direct, but you are still uploading to their servers.

What kind of setup are you looking for on this? Computer to Computer, Computer to local server to computer, or adding the internet into the mix at all?