I wrote a little applescript to make ToDo entries from Quicksilver. Of course, you need to put the script in ~/Library/Application Support/Quicksilver/Actions first. :-)
To make a ToDo, enter text in Quicksilver (or load some selected text) and run the script.
It prompts you for a title, tag, and a due date. This is important to me because I use tags as contexts for my ToDo list. So my tags are @phone, @computer, etc...
You should see a new ToDo in Journler with your title, tag, and due date with the selected text as the body. I got the idea from some scripts by jgrafix and wyzewoman in the Journler forums.
I might also mention that I use Daniel-Jens Kusterer's excellent ToDo2iCal script for putting Journaler ToDo items into iCal. Anxiety makes it easy to see those ToDos that end up in Mail.ical.