I don't know if this has been covered or not, but you can access the N900's file system from an FTP program (I assume all, but I use Cyberduck).

I'm familiar with unix commands, but it's a lot easier to drag the file to my desktop, open it with Text Wrangler, change what I need, and upload it to the N900 again. I just can't see myself editing say, a .conf file on the 900 when I can do it from a proper computer.

You must have rootsh installed on the 900.

Doing things this way will either help more members brick their N900's if they don't save a back-up copy of the file(s) they are changing) or make their lives easier with learning the file system.