Dropbox can sync any folder automatically, so you don't have to do any manual dragging or anything. I have it set up to sync my documents folder, and some random application support folders between two macs.
It's a bit tricky to set up and i HIGHLY RECOMMEND BACKING UP BOTH COMPUTERS before doing this. the first time I did this, I did a step wrong and lost my documents folder! Time machine saved my butt!
Here is a pretty in depth tutorial on how to do it. It focuses on your documents folder, but it works for any folder you want.http://blog.fosketts.net/2011/03/03/mul ... c-dropbox/
Hope this helps,