Cloud Computing / Sharing files among multiple Macs

Greetings,

I'll start by saying that I briefly searched for my answer on the board with no luck. So sorry if it's out there but I couldn't find it.

To get to the point, I have two main macs (desktop & laptop) that I use interchangeably. I would like to be able to access the same files with both computers and more importantly, stay in sync with those files. Example, I work on my FileMaker Pro database on my Mac Pro, then when it's time to leave for the office, I have to copy the file over to my MacBook (if I remember to do that). Which means that I always have two files out there at the same time. This has been ok to deal for one file but I'm finding more and more apps that I'd like to share the files with (Things, Quicken, Filemaker, iBank, OmniFocus...etc).

I do have a MobileMe account (prev .mac) but not sure if I can do it with that or iDisk. I would love it to work as seamlessly as my Mail, Address Book, and iCal syncs with MobileMe. What Mac or 3rd party options do I have for this feature/service? And can someone explain how it would work? Meaning, when I launch an app like iBank, would my app be working on the file in the "cloud"? or would the service/app push the file down to my computer for me to work on it locally and then push it back up when I close the app?

Hope my question was clear but here it is again;

What service or application will allow me to share files between my Macs?

Thanks!