I use Filezilla for FTP uploads etc. Keeping accounts in sync across machines has been a hassle until now.
I suspected there would be a way using Dropbox - and it turns out there are three:
1) Use a portable version of Filezilla installed in say \Dropbox\software\
available from Prortable Apps:
http://portableapps.com/apps/internet/filezilla_portable
2) Reconfigure Filezilla to look for it's config files in your dropbox rather than the programs installation folder. Details here:
http://www.justinmontgomery.com/sync-and-secure-filezilla-with-dropbox
3)For Win 7 and newer, Mac OS or Linux use Hardlinks or Symbolic links.
it involves moving the confiv file and making a symbolic link using the mklink command or equivalent:
mklink “C:\Users\peter\AppData\Roaming\FileZilla\sitemanager.xml” “C:\Users\peter\My Dropbox\Settings\sitemanager.xml”
More details here:
http://www.code-zen.net/2009/syncing-filezilla-sites-across-computers-with-dropbox
I'm still on XP on most machines so I took approach 2.