You can drag URL's from KDE applications ( like kfm or kmail ) or from Netscape into the Caitoo main or dock window. Then you choose directory and filename, under which you want to save it.
You can open transfer from menu or by keyboard shortcuts Ctrl-o or Ctrl-v. Ctrl-v is especially useful if you use a WWW Browser which does not support KDE drag and drop protocol. Copy the URL to the clipboard, then use Ctrl-v in Caitoo ( or simply press a toolbar button Paste transfer ). Caitoo will then open a dialog with pasted URL, which you can edit.
You can pass URL to Caitoo as an argument on startup :
> caitoo some_url |
The same approach works when Caitoo is already running. Instead of starting another copy of Caitoo, it will add argument ( URL ) as a new transfer.
With a distribution comes also a little shell script called caitooclient. This script does nothing else then invoking Caitoo with arguments and redirecting standard output and errors to /dev/null. This might be useful when calling Caitoo from some external programs.